If you look up my article on performing this trigger install, it contains a link to Timney's website. The link is to a video produced by the Timney Trigger Team and it walks you through a simple Step-by-Step procedure that's absolutely worth watching.
Just keep in mind that their procedure is on an AR15 and not a TAC15
crossbow, so there are one or two minor differences. My installation instructions were written specifically for the TAC15 and 15i. It provides the different steps for the 15i from the 15.
Watch the video and then read my instructions. It couldn't be any simpler.