Glad to hear they work and you don't need to get a new set of tumblers and keys. I use my keys in the door once a week or month just to be sure, and I rotate keys. Seems like overkill but no telling how many times the key has been turned in the ignition cylinder in 292,000 miles, first 16,000 it was a rental.
While you can add a personal code, you can't actually change the existing one. You can also set new personal codes that have a personality attached, or don't (so you can have a key code for driver 1 with mirrors and seat, and driver 2, etc, just like the key fob).