I purchased the Haynes manual for my wo Cadillac. It lists step by step on how to. It was not too hard to do but it took about one hour. The bcm was a little tight to remove and install. You have to remove the globe box. Unhook the negative cable on the battery. Remove the two connectors to the bcm. This was not too easy, just keep pulling. Remove the two nuts holding the wire cable brackets. Remove the next two nuts and bcm is ready to pull out. Open the cover on the bcm and remove the prom. It says to use a special tool but you can remove it by pulling with your fingers. Install prom in new bcm the same way it came out. Reinstall the cover and reinstall the bcm.