I used the 8mm open end wrench for the nut on the GPs, then either a 12mm wrench or socket on the GPs depending on what was easier to reach them with. I just changed all 5 in my 300SD yesterday, took about 2 hours. (Tom if you can change them all in 20 minutes you need to be on a pit crew!) Wish I had some ratcheting wrenches. I'll pick some up at Harbor Freight next time, $8.99 for a set! The GP next the firewall is difficult to reach. Hope you have small hands!
John
