ArkSlim,
Using the tool bar on the Forum's Portal... selecting the "User CP" which is located on the far left side of the tool bar.
There will be a drop down menu... select "Edit Avatar" .....
Select the button next to "Use Custom Avatar" ...
Then load what ever you want to use... such as a Photo... or a Jpg file... Just remember these need to be sized small.
It states on the bottom... Note: The maximum size of your custom image is 80 by 80 pixels or 19.5 KB (whichever is smaller).
Good Luck !
Marv