If you look at the top end of this page,there is a similar question and answer. Assuming again that you can't see it,the thermostat housing if not on the side of the cyl. head,will be on the front of the head. If so this means the cambelt covers and belt off for access.Once exposed,the thermostat housing can be removed as normal. Recommend changeing the belt anyway,if close to miles for replacement.Remove the temperature transmitter until bubbles have stopped when refilling with coolant.