Delete an Employee
Go to Payroll -> Employees. Click on the employee name to edit.
Change the 'Status' field to "Inactive" and click 'Save'. The Status field is located in the Payroll section and you may need to click on Additional in that section to see the field.
Setting an employee as inactive will stop them from being charged as part of your subscription.
To delete the employee, go back to Payroll -> Employees and click on this employee. There should now be a 'Delete' button available at the top.