New to the forums, but after looking at different trigger kits, I went with the PRP ultimate match kit. I don't have any gunsmithing experience but the instructions for fitting are easy. also just looking at the old sear will quickly show you how much material to remove to start off.
I used norton sharpening stones for the fitting, starting with a course grit to remove material then used the 1k grit, 4k grit then the 8k grit which left a very sharp flat surface with a mirror shine.
I also had to remove a small amount of material on the back of the sear to allow the grip safety to work properly. I liked using the stones instead of sand paper because of the grits I had available and because of the flat surface I know I'm working with along with ease of material removal and surface finishing.
This trigger kit though is something I highly reccomend because of the major improvement in proformace as far as how the trigger feels and ease of use.