On open I found that my front case (seen in Step 3 that is attached with small screws) had corroded and instead just peeled off the front plastic piece, rather than having the back pop out. In some ways this made it easier to see the opening of the back, but it also made the track wheel fall out.

This experience is obviously no fault of the guide here, but worth noting that this might occur to your old ipod.

Otherwise fantastic website. I've never fixed anything more than replacing shoelaces in my entire life and I got this done. My ipod seems like it will work - I am currently loading up the charge to calibrate the battery. Thanks ifixit!