E.F.
No good suggestions just that my son was the same way and I just pinned him down and did it as fast as I could and wouldn't worry about how perfect of a job I did. He will eventually learn that it won't hurt him and it's all fine. I believe at about three years he was fine so you only have a little bit of time to go before he gets over this phase. It's not a choice, it needs to be done. Once he gets this message it will all be good.