I just finished mine. I bought the new style Fleet Guard shell and cartridge assembly, the one that has the big Cunmins "C" on it. I also ordered an extra cartridge. Got them from Geno's Garage for $91.17 including shipping.

I did it in the afternoon, so it was too early (for me) for a beer. I tried to do it from the top and from the bottom. I got it loose from the top using a filter wrench. Man the factory had that baby on there tight. I could see there was no way it would come out through the top, too much stuff in the way. I may have gotten it out the bottom, but decided to take the wheel well and wheel off. That wasn't bad at all, just a little time consuming. I'll do it that way next time.

The old one is black, I'll change it sooner next time.

Thanks for the writeup Squid.