Hi love,
1. click the Profile tab
2. Hover over Modify Profile tab until drop down menu appears.
3. Click Forum Profile option
4. The top section is Personalized Picture, radio button defaults to Choose Avatar from Gallery, but you can specify the URL of picture with Specify Avatar by URL, and you can upload a picture from your system with the Upload an Avatar button.
Voila. Let me know if you have any issues.
Your friendly neighborhood geek
