Upload the picture to your computer. Click "User CP". It's just below the Betta picture at the top of the screen. Then, you click "Edit Avater". Then click "Browse" or something and then choose your picture. Done. ;) I thought it was called a profile picture at first. :D
Over hundreds of bettas die in their small, dirty cups each day. Only you can help them live. Research and then save them, today!