I want to change to a bigger uSD card in my Fire HD 8 2017. The Fire has put stuff on the smaller card. Do I copy that card to my PC, then copy back to the bigger card? Will my PC understand the Fire card format?
You should be able to connect the tablet to the computer via USB cord with the SD card still in the tablet, and then move the files over to an empty folder on the computer. Then, once you have replaced the old card with a new SD card, do the same in reverse.
Just remember that the device has a size limit for the card. I believe that one is 256GB max.