To do this you will need the factory code, it is located on the computer it is located on the left rear of the engine compartment and the 5 digit code you are looking for is usually in big bold numbers. If you can not read the numbers or find them you can get the code by having the computer read using a factory scan tool, there could also be a card in the glove box that has this code on it if so that would be the easiest option. Below is the process to program your personal code into the system after you find the factory code.
KEYPAD PROGRAMMING1. Enter 5-digit permanent entry code at keypad. Within 5 seconds of pressing last digit, press 1/2 button on keypad to activate programming mode. Hold 1/2 button for more than 2 seconds to erase all stored customer codes. Door locks will lock and unlock to confirm all codes are erased. Existing codes do not need to be erased to program new codes. 2. Enter new 5-digit keypad code. To associate new code with personality position No. 1, 2 or 3 press 1/2 button within 7.5 seconds of entering last digit of new code for position No. 1, 3/4 button for position No. 2 and 5/6 for position No. 3. Doors will lock and unlock to confirm new code is programmed. If another code is to be programmed, begin entering code within 7.5 seconds of pressing last button. 3. After all new codes are programmed, a new remote transmitter can be programmed within 7.5 seconds of pressing last digit in keypad code. To exit program mode, press keyless entry keypad buttons 7/8 and 9/0 at the same time or wait 5 seconds for driver door module to exit automatically.