Mroll's suggestion is valid, but basically you have the option of programming your MX-1000 any which way. You can re-write the text on buttons via remote control (sans pc), then learn the changes from your original remote control. Once that's complete, you can upload your changes to the pc in order to archive/save the information.

Or you can re-write the text on buttons via pc (sans remote), then download the information into the remote control, then learn the changes from your original remote.