I attempted to change the spark plugs on our '04 Grand Prix and stopped once I realized I couldn't pull the spark plug wires off the plugs located at the firewall side of the engine.
I looked at my Haynes manual and found that I need to disconnect the battery cable, disconnect the air intake hose, remove the coolant over flow tank, and then the motor support bolts and tilt the mounts up and use a pry bar to tilt the engine forward to allow more room to replace the spark plugs.
I looked over the forum and saw that someone uses a ratchet strap to move the engine after unbolting the motor supports. I think my Haynes manual doesn't cover the 2004 to 2008 Grand Prix models very well and I can't see why I need to remove the coolant overflow tank.
Any insight of the best way to tilt a Series III 3800 engine to change the rear spark plugs?