This works best if you have a somewhat complicated name. Go to the player's club booth, and explain that your name is spelled wrong, or in the wrong order, on your player's club card and driver's license, and ask to have the spelling corrected on your card. Do you have more than one mailing address that you can use? Ask the booth to change you to a different one. Same with email addresses. Then, next time you play, hand the SAME driver's license to the pit critter, and ask for a player's card. Odds are you'll get a card with a new number. It's possible something may happen eventually to cause the casino to merge accounts, but this usually works for a long time.
It's lawful in California and many other states to use any name you like, whether or not it's the name you were given at birth or through a legal name change, as long as you don't do so for fraudulent purposes.