Download How Do You Change Your Profile Picture Images. (you can also get there by heading to settings > accounts > your info.) however you get to the accounts screen, you'll see two options for changing your picture. To change the picture, hit start, click your account picture on the left side, and then click the change account settings command.
Click on your photo, click on profile, click on update photo.
To change, edit, or delete your profile photo: Select the picture you want to use. Once you choose a photo, you can reposition it by clicking the image and dragging it up. On your computer, open gmail.