if you’re in the UK, this might be a better option than trying to import the right battery:

https://ipodparts.co.uk/ipod-classic-bat...

what jim says. that pic of the clips should be up here so you can visualise what you’re trying to do, before you trash the rails.

I decided not to use the adhesive on the new battery- why make life difficult for the next time the battery needs swapping out? the cells will rattle if you don’t fix them somehow, though, so after I was sure everything was working (coconut battery app can read make & s/n of new battery, & states capacity as 110% of original, which is nice), I tucked a couple of iphone screen cloths in there instead.

I managed to lift the smaller cells away from the case just with the ifixit card & patient force. I used a few drops of goo-gone under the larger cells & to clean up the residual glue. I could definitely do this a lot quicker next time.

thanks all at ifixit!

you must lift it absolutely vertically, or it fouls against the locator pin in the corner- you can easily get the impression that it won’t come over the end of this pin- almost like it’s rivetted in. it isn’t. get a good grip on it with the tweezers in the centre hole & one of the sides, & lift it STRAIGHT up.