You doing it in the air or on the ground?

Either way, put a jack with a block of wood under the oil pan, remove the rear subframe bolts, the two 10mm and one 24mm (I think) on each side. Then you can get up in there and have at it.

 

I haven't done this job on the X, but this job looks similar to the front sway bar removal/install on a GM "W" platform (Grand Prix, Intrigue, Regal), which I've done twice. According to the GM factory service manual, the steering shaft must be disconnected from the rack, then the back of the cradle supported with a jack, unbolted, and tilted down just enough to provide access to the bracket bolts and to slip the sway bar out the back (between the cradle and the body). However, I (and many other folks posting on the Grand Prix forum) was able to unbolt the brackets with the cradle in place and without disconnecting the steering shaft, then remove/install the sway bar out one side. Very little space is available to work the bolts. I used a standard box wrench - about 1/8 turn max before flipping the wrench over. Fishing the sway bar in and out was also a pain, but still far easier than disconnecting the steering shaft and tilting the cradle.

I have no idea if a similar approach will work on an X, but if so, I would suggest go easy and use lots of penetrating oil on the bolts. Also, be extra careful starting them back in, which is not so easy to do when you're trying to squeeze in new, fatter bushings under the brackets. Having to drop the subframe because a bolt broke off during removal or got cross-threaded during install would really ruin your day. On the up side, if you only need to replace the bushings, the sway bar probably doesn't need to come out at all.

 

You do not need to take out the sway bar. Bushings will come out. I use a gearwrench myself. It is easy job. Take you about a half hour if you never done it before. Lowering the rear of the subframe doesnt require removal of steering shaft. It will hang down enough on its own for you to get your paws in there.