Name: greene Savannah, GA (Sunset 28) (Zone 8b) I have no use for internet bullies!
I only had to prune Opuntia once; my neighbor showed me a way that is safe for both the plants and the people involved.
Get a pair of oven mitts and place one mitt on each side of a long pair of barbecue tongs. Using metal tongs alone would leave gouges in the cactus but using padded tongs will not harm the cactus and will allow you to get a good grip. Then use a sharp machete to cut the plant. I also used the padded tongs to pot up the cuttings once they had dried.
Sunset Zone 28, AHS Heat Zone 9, USDA zone 8b~"Leaf of Faith"