tu mean your user icon? That's very easy. Just go in Profile>Photos. There is a button with a plus sign in the parte superior, arriba right saying "upload new photo". Click in it. subir an image from your computer and then check mark "Make this image my user icon". Then it'll be your new user icon.
Profile, then to the right of where your name and stuff tu like is, click on View más Photos, then click subir New Photo. tu then choose a foto from your computer and remember to check the box that says Make This My User Icon. Then click Upload.
Okay here are the steps: 1. Pick an Elsa picture. 2. Once you've chosen one go to profile. 3. Go to fotos and click subir foto and subir it from downloads. 4. A button says make this my perfil picture. 5. Click subir then there ya go finished.