When employees are no longer employed by you, you can deactivate the employee.
Click on L1NDA (top left) and then on Staff;
Click on the name of the relevant employee in the staff list;
Then you can click on the person-with-a-minus-icon at the top right;
After that you will get the pop-up screen below, click Yes here. The employee is now deactivated and will receive an email from this.
Shifts that are already on the schedule and published are not automatically removed from the schedule after the employee has been deactivated. If the employee in question is in your template schedule, it is important to remove him or her from this before copying it again.