Right, I found a post on here (dunno where sorry

) that gives this method:
1) Remove the knob, gaitor and plastic surround
2) Put something 10mm wide between the stick and the left side of the housing and hold it there with an elastic band or summat
3) In the engine bay loosen the clamp bolt on the end of the gear lever
4) Centre the linkage in the engine bay and retighten the bolt
This should get you close, you might have to fiddle with it a bit to get it just right. I wish I knew about the 10mm trick when I did it, I just had to keep frigging with it untill it was ok, first is still a little stiff, but I think its supposed to be (to stop you changing into 1st unless you have stopped)