How do I change my avatar if there is no save button?

If you go to Learner Home, click the cute cartoon next to your nickname, and the "All Avatars" button in the top left hand corner, you get to see characters for your avatar. Of course, sometimes you can't see the "Save" button. So, simply press "Ctrl-" on your keyboard and you will be able to see the Save button. Repeat this process ("Ctrl-") as many times as necessary.