you need to put some felt or moleskin on your shelf to quiet the thud the launcher arm makes when it makes contact.

first thing to do is put the cord between your bus cable from right to left, if you're right handed, about 3/4 inch below where the cord attaches to rest.

pull the cord tight, where its about to pick up the launcher arm.

draw your bow, let down, pull about 1/8 of an inch more through the bus cable, thus removing 1/8 inch of slack in the cord. this is the most possible amount of rope you will need.

cut the cord

mushroom the end.

tie serving above the cord for about 1/2 inch so the cord can't slip up, it won't try to slip down.

you should be good to go.

check your centershot, horizontal and vertical. you should be 1/8 inch nock high and dead center horizontally. if you're correct horizontally and tie to down bus cable you won't have fletching contact from either of those shooting cock feather up.

you want your drop away rest up as long as possible. just missing fletching as it falls.

you can pull xtra cord through to keep your rest up longer and use a brass nock to secure the rope on the other side of the cable. chalk your vanes. if you get contact with the arm let a little rope back out until you have no contact.

that's just how i would do it.