The trigger pin is held in by the heavy, funny 'U' shaped spring that puts the tension on the loading gate. After you get the grip frame off you can depress it with a screwdriver to get the pin to slide out. Putting it back is harder, and easier if you have three hands or some help. It's quite hard to hold the spring down with one hand and line up the pin and the trigger with the other two hands, then slide it all together. They make a clamp specifically to hold that spring down for you. Not owning one, I usually try to get a screwdriver just right holding the spring, then lean on that with my chest to hold it and use both hands to put the pin and trigger back in. If the screwdriver slips, you start over. And if you get it all back together and the gun doesn't work right, you don't have the end of the spring that presses against the loading gate quite in all the way. Re-do it and you will be fine. It's not as intimidating as it sounds, just is easier with an extra hand. I usually get everything in place, then ask my wife to come and slide the pin back in. Her usual response is 'you took it apart, you fix it.' 44 Man