Ok, go to the top bar of this page, under the logo bar, and you click on PROFILE.
When you get to your profile, on the left hand side, there is a column with choices under MODIFY PROFILE click on the 'forum profile information'
This opens a page with Personalized picture on it go down the page to the place where it says I will upload my own picture click it, choose the picture (within size limits) and there you go.
Hope it helps.