Memorize where the notes are on your keyboard (Bells). If your Bell set has note names imprinted or stuck on them, try to play without looking at the letters. If your Bell set does not have letters imprinted on the keys, you can take a pencil and write them in. You can always just erase the pencil when you don't need the letters any more.
Print these out and fill them in to help yourself memorize notes and how to play them!