You may also want to change the settings in apps that you use to create new files (like the camera) to save new ones to the card rather than the tablet. Once that is done you should then go into the apps that you access the files through (like gallery, etc.) and change the apps individual settings to look for the files on the SD card. Personally I would suggest leaving a copy on the computer as a back up. Once there, and still connected via USB, you can then move or copy the files over to the SD card. To move them all at once, or in large amounts, you can connect the tablet to a computer via USB cord, then move the files over to an empty folder on the computer. Sadly, they usually only let you move one or two at a time. If you want to just move files (photos, videos, music, etc.), not apps, to the SD card you can use the file manager app that is on the device, or if there isn't one you can download and install one to access and move the files.