Ok, on a computer. In order to open pretty much any of the URC remotes, you have to slide a thin knife or flat head screwdriver in along the edge where the darker grey of the back meets the silver of the front. You have to be careful here as a slip will result in a nice trip to the hospital. Once the blade or screwdriver tip is in, rotate the back of the knife/screwdriver down and it will pop the cover up. Do this on the other side and it will probably be loose enough for you to remove the cover. Once the cover is offyou can remove the wire clip that goes to the RF antenna. There will be 4 small screws on the back of the circuit board that you will now have to remove. There is another clip on the top of the remote just to the right of the USB port that you will want to unclip. This will allow you to lift the circuit board just enough to get to the buttons.

Now that you've gotten this far, I hope you are ready for the bad part. The select button is the one button that is not easily removeable. I have never replaced one but it is attached to the circuit board whereas the rest of the buttons are not. At least with the above steps you can take a look yourself and see if it is worth trying to fix. At the end of the day if you decide it is not worth it, perhaps an upgrade will be the best course of action.