I've done it, although I kind of messed up the wire routing and didn't have enough slack to put in the battery, so I had to solder an extension, which then gave me too much wire and I had problems squeezing it all inside the case...sigh. Be careful about that. So, yes it's possible. The second one I did I just followed the directions. the board on the bottom isn't that hard to remove.
Answer to: Battery Replacement Teardown Question