Hello friends!
What is the meaning of this sentence ," let go off me".
“Take your hands off me.”
The more general meaning of this expression is ‘to stop holding smth’.
and it should be “let go of me” 
‘to stop holding smth’.
In which case the sentence would of been ; “Let go of it.”
Your explanation is incorrect Pokeman.
Kitos.
Well, smb or smth, it doesn’t change the meaning of the construction.
Imagine a situation where you are holding by the hand a person who is about to fall out of the window. If you let go of him, he will fall.
(or: If you let go of his hand, he will fall).
Do I misunderstand something?
Yes, and, Jcbabo, thank you for calling attention to the spelling of ‘of’.