You can also book a tour with an accredited tour guide.
For example here : https://www.volcanoteide.com/en/activities/hiking
I just found out that I will be able to access the peak!
By booking a night at the Altavista refuge, they let us climb to the peak in the early morning (only)
Access to the crater
It is advisable to leave the refuge at about 6 am, to reach the Teide crater before dawn.
When you stay overnight at Altavista del Teide Refuge, you are
entitled to access Teide Peak without having to apply for the permit,
which is otherwise required.Source: http://www.telefericoteide.com/en/altavista/plan-your-visit
El Teide from Montana Blanca with an overnight stay at the Refugio Altavista
For the true mountain enthusiast, the only ‘real’ way to
climb El Teide is from Montana Blanca, but to include an overnight
stay at the 60-bed Altavista Hut before rising early the next morning
to reach the Pico del Teide in time for sunrise. This is the one
scenario where you don’t need a permit, but you DO:
- need to be at
the summit early as you must be off the Telesforo Bravo trail before
9am,- need to provide evidence when you exit at the Telesforo
Bravo gate that you stayed at the Refugio Altavista the night before.Be aware that it’s not cheap to stay in the Altavista refuge – €20 per
night for adults at the time of writing.Source: http://www.winstercavers.org.uk/Walk_Tenerife_El_Teide.aspx
Credit:stackoverflow.com‘