I changed my spark plugs over the weekend and it took about 2 hours. I'd like to add a couple of tips.

1. Regarding the 17 mm Mercedes wrench for removing the boots, I just used a standard open end 17 mm wrench to wiggle them off. I gently wiggled the wrench with one hand and had my other hand below the boot to support it and pull on it. Each came off with about 10 wiggles. For the back spark plugs, I angled the wrench to the rear.

2. Stack the socket and extensions: I slipped the 5/8" deep socket over the spark plug, inserted the 3" extension, then snapped the ratchet onto the extension. That worked ever time. To remove the spark plug, reverse that order. Snap the socket off, spin the spark plug the rest of the way, then remove the 3" extension then the 5/8" deep socket. If the socket gets oily, use a flat screw driver to pop the extension off.

I thought it would be much worse after reading these posts but other than taking 2 hours, it wasn't bad.