A. Know that although the cat has the advantage of quickness and lack of concern for human life, you have the advantage of strength.
Capitalize on that advantage by selecting the battlefield. Don't try to bathe him in an open area where he can force you to chase him. Pick a very small bathroom. If your bathroom is more than four feet square, I recommend that you get in the tub with the cat and close the sliding-glass doors as if you were about to take a shower. (A simple shower curtain will not do. A berserk cat can shred a three-ply rubber shower curtain quicker than a politician can shift positions.)
B. Know that a cat has claws and will not hesitate to remove all the skin from your body. Your advantage here is that you are smart and know how to dress to protect yourself.
I recommend canvas overalls tucked into high-top construction boots, a pair of steel-mesh gloves, an army helmet, a hockey face-mask, and a long-sleeved flak jacket.
C. Use the element of surprise. Pick up your cat nonchalantly, as if to simply carry him to his supper dish. (Cats will not usually notice your strange attire. They have little or no interest in fashion as a rule.)
D. Once you are inside the bathroom, speed is essential to survival. In a single liquid motion, shut the bathroom door, step into the tub enclosure, slide the glass door shut, dip the cat in the water and squirt him with shampoo.
You have begun one of the wildest 45 seconds of your life.
E. Cats have no handles. Add the fact that he now has soapy fur, and the problem is radically compounded. Do not expect to hold on to him for more than two or three seconds at a time. When you have him, however, you must remember to give him another squirt of shampoo and rub like crazy. He'll then spring free and fall back into the water, thereby rinsing himself off. (The national record for cats is three latherings, so don't expect too much.)
F. Next, the cat must be dried. Novice cat bathers always assume this part will be the most difficult, for humans generally are worn out at this point and the cat is just getting really determined. In fact, the drying is simple compared with what you have just been through. That's because by now the cat is semi-permanently affixed to your right leg. You simply pop the drain plug with your foot, reach for your towel and wait. (Occasionally, however, the cat will end up clinging to the top of your army helmet. If this happens, the best thing you can do is to shake him loose and to encourage him toward your leg.) After all the water is drained from the tub, it is a simple matter to just reach down and dry the cat.
In a few days the cat will relax enough to be removed from your leg. He will usually have nothing to say for about three weeks and will spend a lot of time sitting with his back to you. He might even become psychoceramic and develop the fixed stare of a plaster figurine. You will be tempted to assume he is angry. This isn't usually the case. As a rule he is simply plotting ways to get through your defenses and injure you for life the next time you decide to give him a bath. But at least now he smells a lot better.