Apparently, it’s complicated.
The safest border crossing is Puerto Carreño to Puerto Ayacucho by boat. Before you go in Colombia, do these:
Then buy a Venezuelan insurance and go to SENIAT, Venzuelan customs.
Once done, boat over, then 100 kms to Puerto Ayacucho to get your passport stamped (three months for Europeans, free of charge).
Reference from here.
Credit:stackoverflow.com‘