I'm sorry, I don't understand what you mean.
You can either upload one of your own or choose from some already in the system.
If you follow the link I gave, it's pretty self explanatory.
Edit: If you choose one from the list, you have to click on the circle that is at the bottom left of the avatar, next to the the name.
If you want to upload your own pic, scroll down, click Use Custom Avatar and either upload a picture from your computer or use the url from another web site.
Always remember to save it
