What FCG are you using? Might make a difference for some of the stuff.
But to get the carrier to fit the receiver, need to remove about .040" off the bottom of the rails. Don't forget to take off the part that hits the firing pin first, and the sear catch/notch needs to come off.
I'll put up a couple pics tomorrow, I think I got them from Pirate, but at least you can get started on the little I gave you so far.
I'm working on mine now, and was planning to put up a rough build tut after I get it done.