Just for reference - 2wd head

The exhaust side plugs have a seat behind the top of the plugs so hit them at the bottom with a punch and hammer until they turn then pull through with long nose grips

The front just pushes through and can be removed through the hole for the thermostat

The inlet side don't have any seat and go straight through - i would recommend drill and tap the centre, fit as socket over the outside of the plug resting on the head and screw a bolt with nut & washer though the socket and manually wind out.

To refit they are slightly off shape so get the best fit - smear a very small layer of silicon on the outer edge and knock in straight with socket and hammer

Job done

Well thats what i have done