I mounted one of these on my Magpul MOE and it came out great. I used the instructions here and from the links on the IWC site.
Here are some things that worked for me:
1. Put masking tape on both sides of the area you are going to mount the socket.
2. Use a Forstner bit as it cuts a clean hole. Drill a pilot hole before using the Forstner.
3. Put a small piece of wood inside the handguard opposite the hole you are drilling to 'catch' the bit so it doesn't damage anything.
4. Make dimples for the set screw holes. If you can't fit a drill bit in there, use a mandrel bit on a Dremel tool. Put lock-tite on the set screws when you install them and don't overtighten.
5. Before drilling check the placement of the socket as the MOE heatshields may come in contact with it. Otherwise, you may have to do some filing.