Sticky provided by our very own Farmkid.
If someone knows a better/easier/more official way, please post it; but here's what works for me:
Note: do all of this over a box or other container, because you WILL drop the mag button spring before you're done, and it's very small.
1) Remove both grips and the safety and safety spring on the left side.
2) Hold the frame with the barrel pointing down, and the left side toward you.
3) Lay the mag release spring in place. You'll probably need a pair of long, thin tweezers for this. (There's reason that the cheapo Made-In-China tool people at gun shows sell these. Buy some in straight and bent.)
Bonus suggestion by jeffchance: a slight dab of grease on the spring can stick it in place.
4) Carefully insert the mag release button, making sure to not knock the spring out of place. To do this, point it up over the spring on the way in, and then let it come down on the spring when the button has reached the inside of the right side of the frame.
5) Touching the right end of the button through the hole in the right side, work it down until it can pass through the hole. Hold the button in the down position of the left side: the button and spring are now in the correct position.
6) Reinstall the safety and safety spring now with one hand while keeping the button depressed with the other. Carefully position the left grip, sliding it in over the button, and screw it down. The button is not going anywhere at this point.
7) Complete any assembly on the right side and replace the right grip.
I hope that this is clear, but feel free to ask about anything that's not. Good luck!
If they don't trust us with guns, how can we trust them with the government?
"If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen". Samuel Adams,