Jim Christian wrote an excellent user review on this site last July on the MX700. One of the things he discussed was
opening the MX700. I hope he doesn't mind me cutting and pasting his words onto here. Here's the excerpt from his user review:
K. Opening the MX-700 (only if you have to):
1. Opening the remote is by twisting the body casing so to unlatch the clips holding the 2-MX-700 top and bottom pieces together. Here’s how:
a.Hold the remote horizontally, with the IR plastic window in your right palm (the top of the remote near the OFF and POWER buttons) and the bottom of the remote in your left palm (near the MX-700 words).
b.Twist the remote back and forth in your palms until you hear the clips unlatching all around the remote. You must twist hard to do this.
2. This will probably void your warranty if you do it.
I'd pay attention to that last line! :)
good luck!