The XT hubs are not complicated. The seal pops out and is not as fragile as the tech documents would have you believe. Just remember what side goes toward the canter.

Here is a good discussion about bearings. It is easier to replace them when servicing the hubs than to clean the old ones. I clean them for a couple of services, and then replace.

http://www.parktool.com/blog/repair-...ramic-bearings