

Does that happen to be a variant? I replaced the battery in my aunt’s iPod Touch 6 a few years ago and did have to desolder the battery ribbon cable as it was directly soldered to the logic board. Took a lot of patience just getting to the battery too (screen is held on by glue unlike the clips/tabs in an iPhone).
Also interested to hear other people’s thoughts on reusing these old iOS devices, got one sitting around just collecting dust.

If OP indeed has the 6th gen iPod Touch, not the classic, it won’t be as rosy as most of the comment here suggest. From my experience replacing the battery on one, you need a hair dryer to loosen the glue and pry off the screen, then a soldering iron to replace the battery since its ribbon cable is directly soldered to the logic board. No storage expansion or custom firmware is available for such iOS devices, as far as I am aware.
Also watch out for low-quality replacement batteries, the first replacement I tried only lasted around an hour on a full charge.