I had a windows home installation too, local rules may vary, but mine (India), I could turn it off from the command prompt.

manage-bde -off C: (or any other drive) was what I used.

Edit: nevermind, you meant that you wanted to change the key. That’s not possible, unfortunately, you might have to use some other encryption software.

Bit late to this thread but I know a few commands that might help if you’re stuck:

manage-bde -off C: (or any other drive) This decrypts the volume and turns off bitlocker

manage-bde -lock/unlock

manage-bde -protectors -get C: (or any other drive) This displays your 48-digit key. I suggest you store it somewhere, just to be safe.

Get-BitlockerVolume reveals which of your partitions are encrypted with Bitlocker.

Disclaimer: I am not a terminal nerd, I just had similar problems years ago and went down the rabbit hole, used these commands and turned off bitlocker permanently. I don’t use windows anymore, but when I did, it didn’t cause any problems with bitlocker after this. If you’re concerned about your un-encrypted hard drives, consider using Veracrypt (carefully!) or similar open source encryption software.