well the long bit of it wants to go under the lid tab bit (from when its closed) then the other bit of the spring slots nealy into the side, so looking at it from the back the flat bit wants to be under the tab or behind it when the lids open and then the rest of the spring goes to the left(it probably doesnt matter but thats were mine is
youve got to insert the spring into the gap on the left shell (looking from behind the gun), then insert the lid rod, then slide on the lid 90 % of the way, then use your fingers or a tool to pull back the exposed part of the spring to slide the lid on the rest of the way
oops, think i need a new lid spring now after so many wrong attempts, think ive bent it ,cheers for your help guys, i was doing it all wrong ill attempt it the way you say when i get a new spring ( or try to unbend this one )