You don't need to unhook the batteries or anything, just unhook the connector from the back of the injection pump. Look at the connector on the VA, you will see how the slide comes out and unhooks the cable, then you install the VA and slide the lock in to lock it in. Then connect the truck harness to the other VA cable and slide the lock. Make SURE the slides cam the cable into the connector and it locks firmly in place, you will get a DTC if you don't. Make sure the slide clicks into place, you will feel it lock, and you are home free.