Steps:
1: Use a picture that is right for you, left-click that picture and do save-as and then name it.
2: Hover over your icon on the left. It should be next to an envelope and a flag.
3: Look down, you will see "Avatar" as one of the options
4: Click "Avatar" and it should say on the right "use custom avatar."
5: Click "use custom avatar" and browse your computer and click "Open"
6: You will then have your avatar up!