You don't uninstall a file, you uninstall a package. Make a note which package(s) the file installed (apt-get will tell you). You can then uninstall it by apt-get remove <package-name> (or apt-get purge <package-name> if you don't want any configuration left behind).

reboot the phone to see if the red icon changes to skype icon.
remove skype should be:

(password = rootme)
correct me if I'm wrong guys