I just did the front one over the weekend, and it took me ~45 minutes. I even did it with the car on Rhino Ramps.

You'll need either a 22mm or 7/8 open-end wrench. The 7/8 isn't a perfect fit, but it's close enough. Try getting under and loosening it first (follows standard threading principles of righty-tighty). If it's hard to loosen, start the car and let it idle while you go inside and dig out an old flannel shirt. The flannel shirt will protect your arms from warm undercar parts, and the warm exhaust will hopefully have expanded enough so that you can loosen it without using beat-up tools.

The most difficult thing I encountered was getting my not-so-large hands up to the connector. It's roughly over the left-hand steering linkage bellows. I've actually got to run right now, but if you want details on how I succeeded, then drop me a line.

-cj