OK, here we go. I am going to be a bit more terse than usual. If you need detail on a particular step let me know.
1. Fieldstrip gun. Remove slide assembly and set it aside. Lower hammer to uncocked position.
2. Remove grips. Try to avoid removing grip stock bushings from frame.
3. Punch out mainspring housing retainer pin (bottommost pin on gun.)
4. Mainspring housing is removed downward.
5. Cock hammer fully. Move thumb safety to halfway between on and off. You should be able to wiggle it out of the frame here. Note safety plunger & spring; they may become airborne... take precautions.
6. Grip safety falls out, followed by sear spring.
7. Hammer pin comes out from same side as thumb safety. Ditto the sear pin.
8. Hammer, sear, disconnector, and two safety levers fall out of frame.
9. Remove magazine catch by depressing in about 1/8", at which point the screw (ok, it's not really a screw) on the opposite side can be turned counterclockwise about 90degrees. Mag catch can now be removed out right side of gun.
10. Trigger slides out the back. New trigger slides in... remember, rear of trigger bow slants downward. It may be impossible to put it in upside down anyway, I forget.
11. Reinstall mag catch by reversing procedure.
12. Sear, disconnector and a safety lever go in next. It helps to hold the gun horizontally (aka gansta style) so they don't fall out. Attached pic shows relationship of these 3 parts.
13. Hammer and 2nd safety lever go in next. Be sure hammer & sear have proper relationship to each other before proceeding. Check pic if unsure.
14. Insert sear spring, make sure its 3 legs bear on proper surfaces. (disconnector, hammer hook, and grip safety ??)
15. Reinsert grip safety and hold in place while reinserting thumb safety lever. Remember spring and plunger assembly. Flatbladed tiny screwdriver helps hold it in while inserting thumb safety. Hammer should be at full cock position. Tricky operation, need 3 hands.
16. Slide mainspring housing up into place, make sure sear spring stays put in its slot. Also make sure hammer strut goes all the way into mainspring housing, it loves to catch on the edge. Insert pin and tap home.
17. Reinstall grips, you're done.
Ken Mays
Moderator, Maintenance & Cleaning Forum