There are two 1/4'' x 1/4'' blocks on the sides of the lever that I welded to the mag release. They act as a hinge and have a 7/64'' drill rod in them as a holding pin. On the underside of the lever there is a 1/2'' length of 3/16'' rod that acts as the fulcrum, it is as close to hinge as possible for maximum leverage and presses against the mag well. I ground down the bottom of the lever which made a bit of a shelf. The shelf lets you know if your finger is in the right place as pushing on the lever above the shelf does nothing.
It's kind of hard to describe how I made it without having taken pictures along the way. If you have any other questions let me know.