here's how to stretch loops:
1) place loop on your palm in between your thumb and fingers so that it's wrapped around your hand. bring your other hand under the loop and allow the loop to now be over both hands (as if you're praying).
2) open your left hand and place it parallel to the floor with your fingers pointing to the right.
3) your right hand does the opposite (fingers pointing to the left) but it is next to your left hand.
4) slowly begin to move your two hands in a circular position like a hamster does on a wheel.
This stretches your loop.
Justin Miller in his At the table lecture discusses this. Otherwise if the instructions are hard to follow check youtube
good luck