MSH
Howdy WB,
If all ya wanna do is swap the housing, you can wrap a rubber band around the grip safety to keep it depressed, lower the hammer, knock the pin out, and slide the housing out. Slide the new one in, and be careful
to line up the strut. Knock the pin back in. Done! Now...if the sear spring moves, you'll need to remove the thumb and grip safeties to get it back in place.
If you want to replace the sear spring, the thumb safety and grip safeties have to come out.
Cock the hammer. Remove the thumb safety by pushing it up and using your thumb to push the end of the pin on the right side of the frame. It
should pop out. Watch the plunger assembly! If the spring doesn't have a kink in it...it'll leave fast.
Lower the hammer and knock the MSH pin out. Slide the housing out and lift the grip safety out. Lift the sear spring out. When you put it back together, make sure the sear spring legs are on top of the sear and disconnect.
Slip the MSH part-way in to capture it. Lay the grip safety in place...center
the hammer strut up in the slot in the grip safety, and in the mainspring cap. Slide the MSH home, and install the pin. Install the thumb safety. Make sure the pin goes through the hole in the grip safety. Thumb safety snaps in place when it's pushed in and up. You'll have to depress the
plunger into the tube to get the thumb safety in place.
Ba-da boom ba-da BING! Done! Be aware that, due to differences between the two housings and the amount of sear spring pre-load, that your trigger pull can change...Lighter or heavier.
Luck!
Tuner