To update your photo on your account:
-Login to your account.
-Hover over your Name in the top right corner.
-Go to My Settings.
-Click 'Edit' on the account information section.
-You will then find a space to change your photo. Simply click on the "Add Photo" link. From there you may choose to upload the photo of your choice from your computer.
-Once you have selected the photo, click on the "upload" link and your photo will appear.