You can deactivate an employee's account by going to the HR menu/ User management. Then click on the employee you want to deactivate.
A window with the details of the employee will open and at the bottom right you will find the options Deactivate and Save. To permanently deactivate the employee, click on Deactivate.
Please note: For revision reasons, an employee cannot be permanently deleted, but only deactivated.
As soon as the window closes, the deactivated employee is in inactive status.