hey i guys i need some help with reassemblying my hk usp 9mm (V1). i detail stripped my slide with one problem. i got the extractor but getting the firing pin back in is a pain in the freakin butt. i messed with it for 3hrs last night yeilding no results. i need help. any pointers you guys can give me or videos you can direct me towards???? thanks i appreciate it.