If you have a Flemish twist string, just separate the two bundles and slip in the wool silencers. The string will then tighten up on the wool when the bow is strung. You can also tie them in with some thin thread to help keep them from moving.
I usually tie mine about 12 inches from the limb tips. Seems to work as well as the set-up for harmonic dampening, which is to divide the string length into fourths and thirds and place one silencer 1/4 of the string length from one tip, and 1/3 of the string length from the other tip. For example, on a 60-inch string, the top silencer would be placed 15 inches from the loop, and the bottom 20 inches from the loop.
Might need to try different adjustments until you find what works best on your bow.