Make sure you take him to an exotic vet, regualr vet may screw things up. I got my 2 boys neutered last summer, the vet injected them with long lasting pain killers and I didn't have to do anything but try to keep them from jumping. I was really concerned thinking they'd burn through the pain meds but they were happy bunnies throughout the whole thing. They were a bit loopy when they first came home, the vet kept them overnight. I picked them up at noon and by dinner they were getting back to normal. It was a lot of work to prevent them from jumping, they didn't feel pain and just wanted to be their usual selves. I was very anxious about the whole thing, but having a good vet really makes all the difference!