You go to your perfil and click on photos. Once there you can upload the fotografia you want. Then, below the uploaded image, there are three icons. One of which is a teeny person which is make the image your perfil picture. Click it and that fotografia will become your perfil picture. You can also make it your perfil picture by, as your uploading, clicking the "make this image my perfil picture" box and then it will change your perfil picture once the fotografia is uploaded.
