Retrieving passwords from old profile?

I recently due to pc messup reinstalled (fresh) firefox
and saved my profiles folder.(i did not export my passwords...) However they dont register if i drag and drop the
signons.txt into the profiles folder since they seem to be profile specific.
Is there any way of retrieving them?
I desperatly need two of my lost passwords.
Thanks in advance

Found the answer
simply switch
the old
signon.txt
key3.db
with the new and your back

ofcourse this sets some security issues

but im happy :)