Like others here, I have been very happy with the boiling water method. 10-15 seconds covering the nock, then very quickly, I insert the back of my hunting knife, which fits the nock almost perfect, then gently and evenly, roll the knife back and forth to open the nock. Use even pressure as you roll the knife so the nock opens up symetrically. It doesn't take much pressure. Open too much? Back in the water and then pinch the nocks back together. You can tune your nock fit perfectly this way. Serving the string to match your nocks is also very good, but I find I always have to fine tune with hot water. Nock fit is very important!. Good luck. Dave