Relic,
"To install the firmware, place x5.fw onto a small, empty MicroSD card, and power the Fiio X5 on while holding the top left button."
I've never done anything like this before so I have a couple questions.
If I do this will it add a sixth choice or will it replace one of the five already on?
I guess to see what they look like I need to install them so if I don't like one can it be removed easily?
It's really cool you're sharing your work.
It's really easy to do. By loading the modded theme firmware you replace the stock firmware. If you want to go back to the stock firmware you can reload that FW file and it will overwrite the modded theme firmware.
To be clear, it's a "x5ii.fw" file. If it's not the "x5ii.fw" file name it won't find the file or update. Original X5 firmware, "x5.fw", will not work on the X5ii. Also, I've successfully re-loaded all my firmware on the same card that contains my music (the card was formatted FAT32 in the X5), without any issues. Just make sure you place the file in the root of the card and not in any folders.