I remember reading about this and basically you need to get your dog completely used to you touching his feet without him getting paranoid you're going to start clipping his nails. You're meant to sit beside him and just let your hand be next to his foot. Keep doing this until he doesn't care, then touch his foot (all casually, like) now and again. you build up like this until he doesn't give a damn what you do. Then you introduce the clippers. Same thing. Just have them near your hand, then in your hand etc and the idea is he'll be fine with them if you introduce them really gradually....like over a period of days or weeks. I guess the alternative would be for someone to distract him with lumps of roast beef or whatever, whilst you do it? might that be an option?