That video, etc, is a very expensive way to do it. Instead, get the prepped sear and hammer from McCormick (Numrich Arms offers his stuff) and a Sarco long aluminum trigger with stop. Once you get the parts, email me at doddidad13@yahoo.com.
It can be done with the stock parts, too, but you'll need a Tom Wilson Sear Jig, which is about $40, IIRC, and a set of stones ($15 more) and you'l have to drill and tap the existing trigger for a stop screw. The trigger job takes about an hour on the existing parts, but a lot of people aint got a vise, drill, Dremel grinder, tapholder, etc. If you have to buy all that stuff, even at Harbor Freight tools, it's likely to run you well over $100 to get them.