Every summer, part of our end of school ritual is to change from the FM battery doors on my daughter's BTE hearing aids to the regular ones. This used to be a big deal when she had her Phonak Naida aids because the FM door didn't match the pink hearing aid. She recently got a set of Phonak Sky aids. The doors and boots match the hearing aid, so I doubt she'll be reminding me to make the change this summer. Still, the battery door change is a good starting point for what I'm hoping will be a series of how-to videos.
The tool I'm using should have been included in the pack with your hearing aids. If it was not, a thick sewing needle will do the trick.
Swapping the battery doors is pretty easy. Be sure to keep track of that little pin because losing that would surely be cause for a trip to the audiologist's office. The regular battery door makes the aid more water resistant so it's a good idea to switch to it when FM isn't being used regularly.