just out of interest, is this the first time you have taken it apart?
looking at the manual (
http://www.guay2.com/web/manual/Xtreme45_Manual.pdf) its not very obvious, but it may well be the slide pin :wacko: i just cannot see.
unfortunatly i cannot see your pic due to works stupid fire wall :angry:
Edit- worked a crafty round the fire wall

, like Moose said, there should be a notch on the trigger, the other end of the spring needs to be in a way as it pulls/pushes the trigger in the oposing way as you finger pulls the trigger (hope that makes sense)