As this replacement guide works on an external component of the Xoom Wifi, there are no prerequisite steps.
There are two 6.6mm screws that hold ports into place as well as the back panel. Remove these with a T-5 Torx screwdriver.
Apply light pressure with hand and slide the back plate till it stops in this position.
There is a flex clip on both sides that need to be pushed down in order for the plate to slide off completely. Use a plastic opening tool to release the flex clips. They are located under the back cover near the sides.
As soon as the clips are released the back should slide off.
Remove last two 4.2mm screws from the remaining back piece with a T-5 Torx screwdriver.
Once both screws are taken out, lift the rest of the backing out of the way.