If you have your original package, there should be something called "programming instructions". If it's an older motorola phone, you could probably find the instructions on the
www. I didn't deal a whole lot with them, but as I recall their programming wasn't too bad.
Newer phones are beeotch to do. If you want the phone # removed, you need to go to your carrier (or call customer service). Newer phones have unlock codes that are based on some kind of formula that I guess involves the ESN of the phone. Although you could probably find an unlock code generator on the www if you looked hard enough.