First check in 'Manage infrastructure' from the left hand menu to see if the adult is a Primary Leader of any group, and if so replace them with a different adult. Then go to the adult's account and click on the ‘Archive user’ button on the right. This will archive the user and they will have no further access to eDofE:
Select ‘Manage adults’ then ‘Adult overview’ on the left hand menu.
Select the appropriate location details and ‘Archived’ in the 'Status' box, then click on the ‘Search’ button.
A list of archived adult accounts will be displayed. Click in the box to the right of any account you wish to unarchive, and then click on the ‘Unarchive user’ button at the bottom:
You should see this success banner at the end of the process: