I just did mine. It came out great and a light touch drops the mag. I got the tap and matching drill bit at Fastenal. Locate where you want the button to sit and mark holes on release. Make sure you have right punch that just freely goes on pin hole for lever pin. Lightly tap out roll pin, it should not be hard if you have the right punch. Drill first hole and tap it. Make sure alignment is good dill second hole, Remove button and tap hole. The drill bit you get may be a reverse bit, if it does not drill reverse direction. I think the tap will hit the frame if you try it on the gun. I oiled the pin.
John