I've read http://www.vwt4forum.co.uk/showthread.php?t=34048&highlight=5th+
and I've read http://www.vwt4forum.co.uk/showthread.php?t=22159&highlight=5th+
so I understand how to make the change with spanners and pullers and stuff.
What I can't get my head around is what gear sets I can fit that...