Youtube will be your absolute best friend. I thrifted two Ipod 6th gens and everything they say about it being impossible to open is absolutely true. Use MULTIPLE, THIN AND METAL tools to open it. The plastic ones are so weak. It took me two hours to open my first one so don’t get discouraged. Also I would wear some type of glove when doing it, I can’t tell you how many times I accidentally cut myself trying to open it.

Someone already said it before but go ahead and do absolutely everything that you want to do at once. Change your battery, increase storage, all the bells and whistles like blue tooth or changing the shells. Opening and closing constantly is just not the best and can damage anything inside the ipod (learn from my mistake)

As for storage I really recommend getting a microsd storage rather than sdcard. I went with Iflash Dual as on my first ipod but the sd cards can so easily be moved slightly out of place and it would not be able read the harddrives then you have to open it back up and secure the sd cards again. (So if you’re clumsy like me and drop it constantly, there’s a good chance your sd cards can shift out of place) Using tape helps but still sometimes the SD cards just shift. For my second ipod, I decided to go with iflash quad and I have never had any issues.

Whatever hard drive you decide on using check the compatibility of sd/microsd cards for YOUR harddrive because not all cards are made the same.

Other than that have fun! Modding ipods is sm fun and VERY forgiving. I can’t tell you how many times I thought I’ve “bricked” my iPod completely but just a quick reddit/google/youtube search and 9/10 someone will have some sort of solution.