Oh, I feel your pain! My bichon mix was the same way as a puppy! The first time I tried to trim him up, he squealed like a piglet and my gentle baby turned into a biting little tazmanian devil! He's always had a dominant personality, but fortunately so do I!
I don't know if this will work for your pappy, but I used to lay Napoleon on his back between my legs while sitting on the floor and hold a pair of scissors on his face, or against his paws or belly. Not cutting any hair yet, but just so he knew I wasn't going to hurt him with them. Lots of calm praise, belly rubs and treats when he stayed calm. Eventually I would cut a little on his face, paws, or belly and then repeat the praise and treats. It took almost a year before he totally gave up complaining and trying to squirm away. But now when I pull my grooming bag out of the closet he just lays down where he is and waits for the inevitable!
Hope this helps some. Just remember to stay calm and assertive, like Cesar says! Eventually Cody will realize you're not trying to kill him with grooming utensils! If all else fails, a muzzle can help with grooming or even the vets office. It seems to put an anxious dog into a bit of a trance so you can do what needs to be done quickly. I only use it for painful things, like when Napoleon needs blood drawn or the hair pulled out of his ear canals, because no amount of praise is going to make that not hurt.