Should I still be able to terminate employees through the "employee details" screen? Help describes this as one of the methods however the option isn't there.

Hello Gareth9, 

Welcome to the Comunity page, 

In advanced payroll, the terminate button has been removed from the employee details section. 

You now have to run the payrun and the terminate button is in there when you click on the employee in the payrun under the action section you will see the terminate option in there.