Change your Apple ID photo on iCloud.com
Your Apple ID photo appears on your iCloud.com homepage. You can change it at any time.
On iCloud.com, click your Apple ID photo or
in the top-right corner of the window, then click iCloud Settings.Click Change Apple ID Photo, then do one of the following:
Drag an image file onto the photo.
Click “Browse your device for a new image”, then follow the onscreen instructions.
Click Save.
To change other settings related to your Apple ID, go to the Apple ID account website.