To restore an employee who you previously deleted, go to your Account Settings by clicking on the gear icon in the right corner of your dashboard.
Next, click Employees.
Click the blue Restore removed employee link on the bottom left of your Employees screen.
A window will pop open with a list of your deleted employees. Click on the blue Restore button on the right on the line of the employee you would like to reinstate.
Once you click the Restore button, you will be brought back out to your employees list where you will see your restored employee.
Pro tip: Once you restore an employee you can go in and edit their information or permissions if necessary.