As soon as a user is verified, he will gain access to the portal. It is possible to manage the access of a user to the portal.
This can be done by navigating to "my organisation" in the top-right menu.
Then for the respective user please use the actions button.
Removing a user: Suspend
You can suspend users so they no longer occupy a seat.
Click on "Actions" and "Suspend".
Replacing a user: Suspend and invite
A direct replacement of a user is not possible; you should first suspend the user and invite the new user.