problems cleaning firefox portable. asking for advice 5r3e1l

i need to clean firefox portable for space.
possibly and would like by hand.
what can delete and which of this strange named cache folders and sub-folders are right?
can someone pls name the correct paths for deletable stuff?

i will later give a tip on now free it ebooks, like linux sec and ai ebooks in off-topic, if not prohibited before, keep eyes open
and thx for any help!
EDIT i need to postpone it, cant no more. sorry.
and no i dont want to experiment with ccleaner
EDIT to possibly mess sth up.
thx