You've posted several threads on the subject of WWW::Mechanize::Firefox, so some of this advice may have already been given. There are examples in WWW::Mechanize::Firefox::Examples, if you run this and don't have the prerequisites installed this will be clearly reported on the command line.

"i tried to install Perl on opensuse 12.1."

Tried to install it? Did you have problems? If so, you need to explain what what wrong otherwise you restrict the advice people can give to truisms.

"WWW::Mechanize::Firefox; well i am pretty unsure if this succeded"

See above, read and understand How do I post a question effectively?.

Update:

"Note: i have terrible issues on my new installe opensuse 12.1 - i have troubles with Make"

Didn't we address this in do i need to have a better make - all perl-things fail? If it's something else you need to be clear when describing your problems.