The sailorcurt five part videos on youtube, when you search "sks trigger", are great. As points pointed out, lol, put the sear in your vise and be conservative on the amount of steel you file out of the sear! Just file enough of a notch that it looks like it might make for positive engagement, and file, sand, test, and polish from there as per the instructions. Along with the Wolff springs, and a tiny bit of premium grease, you'll find the trigger on your SKS is safer and incredibly better than stock!