Thanks guys, that was a big help. I twisted it firmly which popped it loose near the Light button, then stuck a nail file in there and started working my way around the remote and it came apart without damage.

Unfortunately the OLED screen is attached by a wide flex ribbon that bends 180 degrees and disappears underneath the screen holder and seems to be soldered inside there. I tugged on it in case it just plugs in but it doesn't budge.

My friend also has an R40 that has dimmed considerably over time (seems to be about half as bright as it was when new). I'm concerned that these OLED screens don't maintain their brightness over time so i'm very hesitant to upgrade to an MX-780 now if the screen is going to go dark in a few years.