How do Jehovah's Witnesses understand Hebrews 1?

Gen 18:2 Although the Torah does not mention the names of the angels that went to visit Abraham, the Talmud tells us they were Raphael, Michael and Gabriel. (Bava Metzia 86b)

How do the Jehovah’s Witnesses understand Hebrews 1?

The Jehovah’s Witnesses understand Hebrews Chapter One as an affirmation that the Son of God occupies an intervening rank between the angelic orders and that of Jehovah the Creator within the celestial hierarchy, and that the Son is our ransom sacrifice.

The Watchtower Society teaches with regard to Hebrews 1:2, which states that ‘he (i.e. God—ed.) has spoken to us by means of a Son… through whom he made the systems of things’ (Heb 1:2, New World Translation), that the Son is Michael the Archangel, who created all things save for himself, who was created by Jehovah, and that as the Word of God (Rev 19:13), he was Jehovah’s chief spokesman to the world. For they say that “Jesus Christ is Michael the archangel” (The Watchtower, 4/1 2010, p. 19), and that he “was God’s first creation, and [that] he helped in the creation of all other things.” (The Watchtower, March 1, 2011, p.16). And they say, moreover, that the Son is called “’the Word’…[which] tells us that he spoke for God, no doubt delivering messages and instructions to the Father’s other sons, both spirit and human” (What Does the Bible Really Teach?, Ch 4, 11).

The Witnesses understand Hebrews 1:3 in the following sense. While the Watchtower Society acknowledges that the Son “is the exact representation of his (i.e. Jehovah’s—ed.) very being” (Heb 1:3, NWT), the Witnesses do not understand this as signifying an equality of likeness between the Son and Jehovah, for the Watchtower Society teaches that in regard to equality “the…Son is not equal to God” (What Does the Bible Really Teach?, Ch 4, 12), in respect of the fact that “Jehovah…has no equal” (Ibid.), and that in regard to likeness “Jehovah God is without like” (Insight On the Scriptures, Vol 2, p.394), for they say that “the Son had a beginning, whereas Jehovah…has no beginning” (What Does the Bible Really Teach? Ch 4, 12), and, moreover, that the Son “was created,” but that “Jehovah…created all things” (Insight On the Scriptures, Vol 2, p.394), and furthermore that the Son, the “‘Mighty God’…was not to be called almighty God, as though he were…coequal” (The Watchtower, April 1, 1987, p.17).

The Watchtower Society understands Hebrews 1:4-13 as distinguishing Jehovah’s only begotten Son Michael the arch-angel (i.e. the pre-existent Jesus) from the rest of the angelic creation, for they say that “Jesus is Jehovah’s most precious Son…for he was God’s first creation. (Colossians 1:15)…He is the ‘only-begotten Son’ (John 3:16)…the only one directly created by God” (What Does the Bible Really Teach?, Ch. 4, 11). They say, furthermore, that “Michael [is] ‘the archangel’”, and that the word arch-angel “means ‘chief angel’” (What Does the Bible Really Teach?, Appendix XI), and they affirm, moreover, that “there is only one such angel” (Ibid.). The Witnesses believe, based upon these considerations, that when Paul says “to which one of the angels did God ever say: ‘you are my son; today I have become your father’?” (Heb 1:5, NWT), he does not believe that Michael the ‘chief angel’ is ‘one of the angels’, that is to say, is one of the members of that celestial grouping, concerning which Jehovah has never said: ‘you are my son’. The same principle holds true with respect to all of the Messianic passages to which Paul makes reference in Hebrews 1:5-13.

Finally, the Watchtower Society understands Hebrews 1:10-12 according to the following sense. “Paul”, they say, “[was] inspired to express the truth…that Jesus had a pre-human existence, at which time he was Jehovah's honored agent by whom he ‘laid the foundations of the earth’” (Did Paul Misquote?, R448: pp.7-8, Zion’s Watch Tower, Vol. IV, Pittsburgh, PA, 1883, No. 7). The Society forthrightly assumes that the text of Psalm 102:19-27 transitions from the standpoint of the psalmist in verses 19-22 to that of the Son in verses 23-24a, and from that of the Son to that of Jehovah in verses 24b-27, as they give their readers to understand: “We quote Psalm 102:19-27, giv[ing the] proper sense” (Ibid.). Starting from Psalm 102:19, they quote as follows: (Ps 102:19) “For he hath looked down from the height of his sanctuary; from heaven did Jehovah behold the earth.” (102:20): “To hear the groaning of the prisoner, to loose those that are appointed to death:” (102:21) “To declare the name of Jehovah in Zion and his praise in Jerusalem,” (102:22) “when the people are gathered together and the kingdoms to serve Jehovah” (Ibid.). Having quoted the words of the psalmist from verses 19-22, the Society continues to exegete the psalm as follows: “Now Jesus is represented as speaking at the time of crucifixion” (Ibid.). And thus they understand him to say: (102:23) “He weakened my strength in the way, He shortened my days. (102:24a) “I said, O my God, take me not away in the midst of my days” (Ibid.). That is to say, Jesus feared death, and he wanted to go on living in the world. But the Witnesses explain that Jehovah comforted Jesus during his trial of suffering by reminding him that he was present with Jehovah at the creation of the world, and by reassuring him that he would live on forever after he was raised from the dead. Thus they explain: “Hear Jehovah's answer to that heart prayer.” (102:24b) “Thy years are throughout all generations.” (102:25) “Of old thou hast laid the foundations of the earth, and the heavens are the work of thy hands;” (102:26) “they shall perish, but thou shalt endure; yea, all of them shall wax old like a garment: As a vesture shalt thou change them, and they shall be changed;” (102:27) “but thou art the same, and thy years shall have no end” (Ibid.). The Society teaches, therefore, that the psalm presents us with a dialogue between Jehovah and his Son at the hour of the Son’s suffering departure from the world, and that Paul records Jehovah’s comforting and reassuring words to his suffering Son as he accomplishes his ransom sacrifice on behalf of sinful humanity. It would seem, then, that the Witnesses view Psalm 102:25-27 as a Messianic psalm relating to Christ as suffering servant, and that Paul himself understands it in this sense in Hebrews 1:10-12. It appears that this interpretation of Psalm 102:19-27 – Hebrews 1:10-12 has not been revised or updated by the Watchtower Society, so it seems to stand as the official teaching of the Jehovah’s Witnesses with regard to these scriptures.

The answer to your question has to do with the word rendered “worship” in many translations like the KJV. The New World Translation renders vs 5&6 as

5 For example, to which one of the angels did God ever say: “You are my son; today I have become your father”?+ And again: “I will become his father, and he will become my son”?+ 6 But when he again brings his Firstborn+ into the inhabited earth, he says: “And let all of God’s angels do obeisance to him.”* (footnote * bow down to him )

Jehovah’s Witnesses teach that only Jehovah is due the highest form of adoration and worship. The Greek word that is rendered worship in Hebrews is proskyneo. It is used elsewhere in the scriptures and need not refer to the same level of homage one would direct to the Almighty. Consider Matthew 18:26 where the parable about the man who owed a great debt to another. KJV translates a form of proskyneo as worshipped here. The indebted man fell at the loaners feet and worshipped him. Of course we don’t conclude this means this debtor committed an idolatrous act here.

A discussion on this topic is found here

A key point made for why the New World Translation renders the Greek word proskyneo as obeisance in Hebrews is:

Clearly, then, the word pro·sky·neʹo, rendered “worship” in some Bible translations, is not reserved exclusively for the type of adoration due Jehovah God. It can also refer to the respect and honor shown to another person. In an effort to avoid any misunderstanding, some Bible translations render the word pro·sky·neʹo at Hebrews 1:6 as “pay him homage” (New Jerusalem Bible), “honour him” (The Complete Bible in Modern English), “bow down before him” (Twentieth Century New Testament), or “do obeisance to him” (New World Translation).

So the point is that Jesus is not just another angel but the first of all of Jehovah’s creation (the chief angel Michael )and the one through whom all things including the multitudes of angels were created. Jesus thus deserves high honor and deep respect from the angels but this does not rise to the level of worship and devotion that is exclusively offered to the Almighty God Jehovah. Additional info on this here