Cut a length of 3/4" x 2-1/4" x 8' stock. Line it up perfectly with the fence on the miter saw and fix it in place.
I screwed mine to a backing piece and fixed it in place with screws to the bed of the miter station... Much easier that way.
Using the drill bit guide line on the back of each 2' track piece drill 5 x 1/8" holes in each one.
Position them to the top rear edge of the fense and screw them in place (screws supplied).
Take off the tape backing and stickit down following the guide that comes with the kit.
Assemble and install the stops and you're done. Just adjust the alignment marks first.
I bought mine directly from the Kreg web site here - https://www.kregtool.com/store/c47/saw-accessories/p107/precision-trak-stop-kit/
It's $139.99 + shipping and tax. Worth every cent. I love this thing.