You need to copy/migrate crap that's stored by default on your phone's internal storage to the SD card. If you don't already have one, you can download a file browser/manager like the free ASUS ZenUI File Manager from the Google Play
https://play.google.com/store/apps/details?id=com.asus.filemanager[HTML_REMOVED]hl=en
Thanks.
Why are some apps easily moved to the SD card with the app manager and some cannot be moved no matter what?