When you say "add it on your profile", do you mean as your avatar, the photo that appears to the left of your posts? If so, here's how:
1. First, you must shrink your photo so that it is no more than 150 x 150 pixels. I'm not sure what photo editing software you might have on your computer to do this with. Once you do that...
2. Click on the button at the top of this page that says user cp.
3. Near the top of the page, click on the words Edit Options.
4. Near the bottom of the page, click on the button that says Change Avatar.
5. At the bottom of the page, enter the full path and file name of the photo file where it says You can upload an avatar from your computer: (or, you can find it by clicking on the "Browse..." button).
6. Click the button that says Submit Modifications.