1) There is probably a screw under the batteries that doesn't play a big part in holding it together, but does need to be removed before taking it apart.
2) There are little hooks built into the case holding it together at several points around it. It is much easier to open once you understand the structure of those hooks. I saw a very good picture of them somewhere either at[Link: hifi-remote.com]
or in the JP1 group, but I forget where.
3) You need several small "tools" for finding the hooks, opening the hooks, and holding them open while you open more of them. I've seen various opinions posted about very flexible putty knives and other things to use. My own experience as a klutz opening many of this style remote with various tools is that there is a single best tool: That is strips cut from that thin clear semi rigid plastic material often called "blister pack" that many products are packaged in. You can force a strip in somewhere, slide it sideways til it encounters a hook, angle it and force it to open the hook, then leave it stuck in that hook while you start somewhere beyond it with the next strip. About half the time you destroy the "tools", but you get the remote reliably opened without damage and those particular tools are pretty easy to replace for free if you remember to when buying products packed that way.