You should be able to find something that looks like ( img src="url" ) somewhere in the code for the profile. You need to upload the image you want to place on the profile somewhere on the internet (such as the gallery section of your character, deviantart stash, or literally anywhere else you can upload an image) and then open that image up in a new tab seperately (so it's a tab with nothing but the image). Copy the url for the image and then replace the url that is already as the img's source and it should appear on your profile.