I use the knife method. Things to consider; was the kid early or overdue, both testicles descended, general condition of kid? Was told by a vet that under one week is ideal age to castrate, for the trauma level of the kid. I cut off the lower third of scrotum, grab the scrotum and push up each testicle, one at a time, and use a pair on hemostats to grab and slowly pull out each testicle. The cord will just snap off with a steady pulling pressure. I do this in the evening. By morning, the new wether is back playing again.