Just start them from terminal.
Type "bitcoin-qt" in the command line and it should start.
You could also create a desktop file to be able to lunch it from your desktop environment.
You just need a file in
/usr/share/applications called for example bitcoin.desktop owned by root (chown 0.0 bitcoin.desktop && chmod 644 bitcoin.desktop) that looks something like this:
[Desktop Entry]
Name=Bitcoin
Exec=bitcoin-qt
Icon=<location of your bitcoin source directory>/bitcoin/share/pixmaps/bitcoin128.png
Type=Application
StartupNotify=false