How old is your chi.
I advise that you start playing with his feet, alot...splay the toes, look at the toenails...playing the game. This gets them used to handling the feet and cutting the nails.
I cut all my chis toenails and all, except one are okay with it. I use a cat nail clippers since the chis usually have pretty fine nails. I have one that has heavy nails, but the cat scissors still works for her, too. I alway have kwik stop or styptic powder on hand, just in case they jump and you draw blood. The squirmy one will start yelping as soon as I pick up the clippers...but she still lets me cut the nails. I just cannot let her have the upper hand, I usually try to do her first, because she is worse if she is last...