Click into the People tab on the left hand side of the screen
Using the Resident or Staff tabs at the top you can search for the person you want to change access for.
Click into the person.
Now click the access tab at the top of the screen.
Click the building that they have access to/that you wish to adjust access for
The next page that loads will have all the units, spaces, and Brivo groups for that building. From here you can navigate to the the access you want adjusted and toggle it on or off.