In order to add people to be able to edit first add them using Space Tools in lower-left corner.

In the drop-down select Permissions.

Then select edit Permissions.

add in user UVA computing ID.

Then Update and come out to the main page and select in the upper right corner the + symbol.

Put their UVA email in to send an invitation to edit.

Note: If you are an admin (or recently got permissions) and if you don't have edit privileges on any of the sub-pages, then navigate to that page > click on the "pad-lock" sign / three-dots on upper menu bar > on  "Restrictions" page, add your-self like in the previous line.