How to Disable Users:
1. Go to Settings > Users
In the bottom-left corner, click Settings, then select Users.
2. Find the user and open their menu
In your list of active users, click the three-dot menu next to the user you want to disable.
3. Select Disable
The user will be removed from your active users list, and they will no longer be able to sign in with their login credentials.
Viewing and managing disabled users
There is a Disabled tab on the Users page where you can see all disabled users. From the three-dot menu there, you can:
Enable -- restore their access
Delete -- permanently remove the user
When a user is disabled, their contact is automatically archived.
When a user is deleted, their contact remains in the archived section of the People tab until it has been manually restored.