Just looked and its definitely there...
Did you miss the step where Rob says click on 'profile'? its a tab in the UCP card, when you're in there the Avatar option is on the left as a button
Thanks Savory...
1. Click on user control panel.
2. Change the tab at the top from overview to the one next to it - profile.
3. On the left choose the 3rd option down - edit avatar.
4. Upload a photo.
5. Have a sit down to recover