A couple things will be very useful to you. First, you need a decent disassembly guide. While we don't have repair guides, we do have a teardown that gives a basic overview of how the Xoom comes apart. Next are the tools; we sell everything that you could possibly need. Our teardown lists a spudger, and T5 and T7 Torx screwdrivers as the tools you need. You obviously know that you also need a soldering iron. You may want to use an anti-static mat and/or an anti-static wrist strap to avoid accidentally zapping the motherboard.
Other than that, the one thing you'll need is patience. You can also take pictures as you go and create some repair guides to show everyone else how to replace the charging port on their Xooms (wink wink, nudge nudge).
I was able to take apart my Xoom and you don't need to solder it from what I can tell. Watch this video: http://www.youtube.com/watch?v=jOPik-u-9...
Basically, take the big part of the back cover off, then remove 3-4 screws from the bottom half of the motherboard, and the two smaller screws from the batteries. Gently pull up on the motherboard, remove the old port and place the new one in.
Where did you get the charging port part? I only found one place, but they want to charge me $50 as they require mandatory service work.