Simple install, though I looked it up online instead of reading the included instructions - and I'm glad I did because it helped simplify the install.
After safe/clearing, remove the bolt and then the barreled action from the stock, drive the forward pin that retains the trigger out left to right (pretend that you are in shooting position, barrel pointing away and trigger on the underside)
BE CAREFUL WHEN DRIVING THE REAR PIN! Do not drive it all the way out! Just enough to clear the trigger assembly. This will prevent you from having to reposition/reinstall the bolt catch spring.
The rear pin is driven outwards right to left.. the opposite of the forward pin.
Once the stock trigger is removed (a sear and sear spring should fall out, as well - they are no longer needed), simply put the new trigger in its place, drive the forward pin in, then rotate the assembly into position to allow the rear pin to be driven in, reassemble in the stock, do a dry function check, and torque.
I had never done this before, and it took me less than 15 minutes. It's a really simple job, and WOW! What a difference over the stock X-Mark Pro trigger. I may eventually tinker, but after testing I didn't have to adjust it any for it to feel "right". Smooth, gentle pull until you feel a little resistance, give it a little more, and *click*. Nice, clean break. I can't wait to test it out!
Getting this on sale was just the icing on the cake.