i'm a bit confused as to what you'r having problems with. Please elaborate more on what you don't understand.

Basically i mounted mine with the mounting bar square on the bow. Then, nock an arrow and make sure it is square with center of the berger hole or as close as you can tell. Then twist the launcher up and make a vertical adjustment to the prongs to lift the arrow up until the bottom of your arrow is centered in the berger hole. This should get you close and you can then recheck that your nocking point on the string is where it needs to be. If you're mounting this on a bowtech with a slide that has a tab on it, you can use this to attach your cable to.

I love mine, its the best hunting rest I've shot to date. Accurate, quiet and strong.