1) It's recommended to format the NEW card in Windows before copying data over to it from the old card

2) Though really any brand SD card should work, Autel suggests using the generic SanDisk SDHC cards (the blue ones work perfectly) since they're closer in design to what's shipped with the DS708. 

Make sure your DS708 is powered off, eject the card, plug it into a computer (Windows is ideal, but works with Macs and Linux too), and copy the contents to a folder on the desktop.  Safely eject that card, put in the newly formatted card, and copy the folder contents to that one.

That's really all there is to it.  Despite some aggressive protection Autel's put in place on the vehicle data, they thankfully didn't put any limits on the media or media size.

I believe the SD card can be named anything you want, by the way, but the default for me was something like "NO_NAME".  Ultimate, it gets mounted at a specific point and all that matters is that your files are stored on it in the same way as they were with the previous card so the main interface and diagnostics files can load.

-Jeff