My Files/Videos. Long press one you want to copy to the SD card, then tap the rest.
Menu key/Copy.
SD memory card.
Choose the folder you want to put them in.
Upper right corner - Paste here.
Once you check that all the copied files are good, go back to Video, long press the same files, trash can (at the top).
The reason you don't move the files is that if a move bombs, you have no file. If a copy bombs, you just copy it again - the original is still there. (If they're important, back them up to your computer, a cloud account, or both. You can never have too many backups.)
07-20-2015 11:29 PM