It looks quite ghetto when I take the rail off the gun. I didn't feel like touching up and smoothing out the parts that aren't visible.
1) Undo the 2 screws indicated in the first picture. The factory screws are torx(star) headed screws. I've replaced mine with hex screws and washers because I had matching nuts for them.
2) Cut the 2 mounting points off the rail so that it is level.
3) Drill out 2 large holes where the nuts will go. Epoxy them them into the rail. There is alot of empty space there. The nuts have to go in at the right angle. I did it by putting masking tape all over the bottom of the receiver and then putting the screws and nuts into place and then putting a big glob of epoxy to hold them in. When the epoxy has cured, unscrew the screws, peel off the masking tape, and dremel off any excess goo that oozed out.
4) This is how it should look once it is dried. Doesn't look so cool now does it?
It is rock solid however. I've tried pulling on the forward grip as hard as I can and I can't get the rail to come off.