I totally agree with Brister. You need to show him who is the alpha. You can gently take his paws in your hands and massage them and so forth to get him used to the feeling. Once he's relaxed, you can try and do the nails. Do at least 1 or 2 before "giving up" This way you will have asserted yourself but not to the point of stressing him out.
If he should try to nip at you, correct that immediately with either a "ouch" or stern "no". He will learn once again that you are alpha. Good luck.
