Just trim a few whiskers or a few hairs on his legs so he gets used to it. He eventually will be fine. My old horse hated the vibrating on his face and i took it slow and he was fine.
If your horse is not being too terrible, and is just dancing around a little especially if you are clipping his legs, you can have someone hold the opposite front leg. This will help keep the horse still, but be careful as if the horse decides to spook while someone is holding the leg, both horse and human can be seriously injured. If your horse has a really bad problem with the clippers and is pulling back, kicking, rearing, excetra, I would either twitch him or use a sedative (with the help of a vet).
Give him lots of treats,
If he moves don’t get mad just let him move
Hello ! If it's the noise that scares him, there are horse earplugs on the market that might make it less scary. Some riders at my barn use it and it seems to work quite well !
Hi ! As Levis said, a twitch is believed to calm the horse by releasing endorphins as pressure is applied, thus reducing stress and pain. You can also use tranquilizer but it's less natural and you have to be careful if you compete !
Hello Mathew :) You can use a twitch, it is holding a large portion of their lip it will not hurt them but calm them. You can usually see this calming almost instantly. It works better for some horses than others but you can definitely try :)