I have owned one of these pistols for a bit and I decided I would start putting together some post involving this pistol as there is lots of good info out there but it's scattered all over the net so here is my attempt .
Buy the parts you need right from the people who built your gun .
Link to the Instruction manual
If you want some very nice Wood grips for your HP22 or Hp25 you need to check out
They also have a very informative .PDF and Youtube video on how to fix a extractor .