This is from doubletapdrew It should help you out. Let me know if you need any help
It comes with a new receiver for the advanced remote. Since you have AP8 this is all you'll need:
2-Way Advanced Remote Start - For Use on Vehicles with Extended Range Remote Lock Control (AP8), and Power Liftgate (E61), Not For Use on Hybrid or Denali Models 19157233 $ 250.00
2-Way Advanced Remote Start - For Use on Vehicles with Extended Range Remote Lock Control (AP8), But Without Power Liftgate (E61), Not For Use on Hybrid or Denali Models 17802071 $ 250.00
Instructions:
Verify the vehicle has the AP8 option and an automatic transmission. Call TCSC 1-800-828-6860 (English), 800-503-3222 (French), or 248-265-0840 (Spanish) to obtain programming instructions to add the remote start feature. You must have the Vehicle Identification Number (VIN) that will be upgraded and the Authorization Code from the kit.
Using the Scan Tool and SPS terminal, reprogram the theft deterrent module (TDM, not VTD). Use Normal mode, and select the calibration with remote start. Refer to Theft Deterrent Control Module Programming and Setup.
Reprogram the body control module (BCM) using the method called out by the TCSC. Refer to Body Control Module Programming and Setup.
Use the Scan Tool to perform the Copy and Paste TPM Information procedure. This will extract the TPM Tire Type information as well as the sensor data from the existing RCDLR prior to its replacement and store this information in the scan tool. After RCDLR replacement, the tire type and sensor data stored in the scan tool is written to the new RCDLR, negating the need to perform the tire type setup and sensor learn procedure. This must be performed BEFORE removing the old RCDLR. Refer to Remote Control Door Lock Receiver Programming and Setup.
Physically replace the factory remote control door lock receiver (RCDLR) with the 2-way RCDLR included in the kit. Refer to Remote Control Door Lock Receiver Replacement. Do not program or reassemble yet.
Remove the factory keyless entry antenna (1).
Clean the areas of the front and back of the rear upper garnish molding (2) where the antenna (1) will be installed and the antenna cable (3) will be secured with a surface cleaner (50 percent isopropyl alcohol, FS-1082 hi-flash naphtha or equivalent).
Dry the molding thoroughly using a lint-free cloth.
Important:
• The adhesion promoter must be used to assure adequate bonding of the antenna.
• Mask off or protect areas before applying the adhesion promoter.
Apply Adhesion Promoter GM P/N 12378462 (Canadian P/N 10953554) to the front and back of the molding where the antenna will be installed and the antenna cable will be secured. Follow the adhesion promoter instructions on the product label. Use a = 212 mm (8 3/8 in) and b = 92 mm (3 5/8 in) for the dimensions on the figure.
Important:
• Position the antenna according to the figure provided.
• Do not touch the adhesive pad on the antenna.
Remove the protective film from the adhesive pad on the antenna.
Align the antenna (1) according to the figure, using a = 212 mm (8 3/8 in) and b = 92 mm (3 5/8 in).
Press firmly all along the antenna, including all four corners of the adhesive pad, in order to ensure proper adhesion to the trim panel.
Hold pressure on the antenna for 10-30 seconds.
Important:
• The antenna cable must be secured at the rearward edge of the molding (not routed directly behind the antenna) for the best performance of the system.
• Excess wire must be looped in a figure 8 no less than 100 mm (4 in) in length, failure to do this will reduce the performance of the system.
Wrap the antenna cable around the rearward edge of the molding and taking out the slack, secure the cable to the back surface of the molding at the rearward edge. Leave c = 100 mm (4 in) length of cable at the connector to connect to the RCDLR. Use five adhesive wire-wraps (3) to secure the cable in a figure 8 no less than 100 mm (4 in) in length.
Connect the antenna to the RCDLR.
Reassemble. Refer to Remote Control Door Lock Receiver Replacement.
The 2-Way RCDLR will not work until it is programmed. Using the Scan Tool and SPS terminal, program the 2-Way RCDLR. Select the controller "RCDLR Remote Control Door Lock Receiver 2 Way - with Yellow Label". Select the options that the VIN is equipped with. After the 2-Way RCDLR is programmed, if the vehicle is equipped with TPMS, perform the Paste TPM Information procedure or perform the tire type and pressure setup and sensor learn procedure. Refer to Remote Control Door Lock Receiver Programming and Setup.
Check the 2-Way transmitter battery for full charge. Press the unlock button on the 2-Way transmitter eight times consecutively and then check the battery gauge in the upper right corner of the LCD display. If the battery icon is flashing, shows two bars or less, or the display flickers or fades out, replace the battery. Only if the gauge reads full (three bars), the transmitter can be released to the customer. To replace the battery:
18.1. Use a lithium coin cell battery, type CR2450 (GM P/N 12493150).
18.2. Gently pry the transmitter halves apart all the way around, using a nylon trim panel tool or similar object, starting at the notch at the bottom.
18.3. Remove the battery and insert a new one, making sure the positive side is down (towards the back of the transmitter).
18.4. Snap the transmitter halves together, making sure the gap is even all the way around.
18.5. Check the new battery. Press the unlock button 8 times consecutively and then check the battery gauge.
Program the 2-way transmitter and the vehicle factory transmitters to the new RCDLR.
Turn the ignition off for 1 minute.
Turn the ignition on.
Using the scan tool, retrieve any diagnostic trouble codes (DTCs) from all of the modules.
Clear all DTCs.
Remove the scan tool.
Operate the 2-way and factory transmitters in order to verify correct system operation. Refer to Keyless Entry System Description and Operation. Press a command button with the vehicle ignition ON in order to synchronize the 2-way transmitter clock (if equipped) to the vehicle clock.
Drive the vehicle above 25 mph for at least 2 minutes. This is to update the tire pressure displays.
Add the transmitters to the customer key rings.
Place the 2-Way Advanced Remote Start owner manual in instrument panel compartment.
Keep the vehicle dry. Allow 6-8 hours, at 15°C (60°F), for the antenna adhesive to cure after installation.