I think that when you first get to the site before you login or just after you can go to your accounts section & you will see it there. I hope this helps

hope someone corrects me if I am wrong, but I thought: go to hoem page, Log in, You see your name and your account.Go with cursor on this and you see a list: one of the items on the list is: add/change picture (the text is in red) here you can change your avatar. At least I thought that's the way.