Press the bow and twist the string so that the peep is positioned so it rotsates where you want it. Or move strands from one side to the other. The absolute best way is to get a good set of aftermarket strings that are built correctly and you should end up with NO peep rotation at all.

Peeps don't really rotate as we think of them. What is happening is the string is twisting. Most factory strings do not have enough twists in them to begin with. There should be about one complete twist for every 1 1/2" of string. You could add a lot of twists to the string which will help stabilizes the strands and make them all work together, but only if the string is long enough to do so.

The biggest downside to this is maybe you end up with an ATA that is too short, if the string is short, and the twisting tightens up the string bundle so serving might get loose. That's why good strings are prestretched, pretwisted, then served.