How do you replace the serpentine belt on a 2000 Cadillac Deville Northstar Engine?

The 2000 General Motors/Cadillac Deville came equipped in the 4.6L Northstar engine. Removing the main belt will require depressing the tensioner to free it. The new belt can then be routed across the accessory drive pulleys. The OE AC Delco belts for this application are 6K815 and 3K243.