Demographic info includes three basic sections:
It also includes two optional sections for Boy Scout Troops for Mic-O-Say (if you use it) and Order of the Arrow participation.
Here's a picture of the demographic form so you can see all the information kept here:
First go to the profile of the person whose information you want to change. You can do this in three ways - by clicking on the Manage Badge and then finding the member you are interested in, by selecting the User Manage option from the Manage badge, or by using the People Powerbar, as shown below:
Once you are on a user's profile, select the demographics tab and click on the edit button, as shown below:
Use the form to make your changes and click save to finish.
Two important pieces of information that are accessible in the demographics section are the profile photo and the medical form. You can upload files for each of these as shown below: