The customization is done by this way.
                                                                                
1. Clicking the button "Customize" in MeML lesson page. A new window will be poped
   out to show the customization interface.
                                                                                
2. Moving mouse in the preview page. The customizable content will be
   highlighted automatically.
                                                                                
3. Clicking on the customizable content and a dialogue will show up. 
                                                                                
4. For the "Waitress" picture, click "Browse" button to upload a new
   picture and click button "Preview". The picture and any menu
   modifications will be changed in the preview page.
                                                                                
5. Clicking the Button "Done" to save the changes or clicking button
   "Cancel" to discard changes.

6. Here is a handy waiter picture to use.
   http://wme.cs.kent.edu/kimpton/javascripts/mealorder/Italian_Waiter.png