+Antonius van Breugel
You should be able to disable pre-installed apps. This will free up some space, although not all of it.
Samsung blocked the ability to move apps to the SD card, they have some reason for it although I cannot remember what it is right now.
Doing things like clearing emails and text messages will free up space. Removing apps that you do not use is obvious. Being sure that all photos, music and videos are on the sd card is another obvious space saver.