I've had to do this before on other vehicles, not exactly the same setup but the key is to have a enough workspace and all of the proper tools necessary. I seem to remember having a rough time with the big nut off the rear of the driveshaft. That nut has to be removed so you can pop off the flange to let you remove the center bearing assembly. Usually you're going to want to make certain that you mark the flanges before you take apart the drive shaft to keep them in balance. Clean it all out and replace everything.
Question, for the $400, what type is the shop going to put in, I assume it will be an aftermarket one, but which one as there are at least four or five manufacturers that make these now. Parts alone is going to be like $130 by the time you're done with it I think, what's the balancing cost for this turn out to be? This seems to be a little bit steep, but you have to pay for their time and this job can be a little bit on the greasy side.