1. Go to 'Edit Profile'
2. Select [upload photos]
3. Select a photo and it will be uploaded
4. Now hover over the picture with your cursor. The following options will appear in the picture:  [main] [x]
 - Select edit to adjust the picture
[main] - Select main to select your profile picture
[x] - select x to remove the profile picture entirely
Note: the x isn't visible on images with a light/white background.