How to bleed air from a 4x4 YB Cosworth Cooling system????

[madmaxptt]

Hi! I have just emptied my cooling fluid from my 4x4 YB Cooling system and I have filled it up with water(mixed with antifreeze fluid), I know that there is a bolt on the top of thermostat housing that helps to release air from the cooling system, does anybody knows how to use it, i drove the car but I see that the ventilation on my radiator opens more frequently than it used to do!
Temperature looks ok on my stock dash but it rises easier than before!!!!

[katana]

I would guess like most 'air bleed screws' - you open it a 'bit', air will escape and then water. When water runs out, close screw! Doesn't mean that all trapped air is out but should get most out if air bleed is highest point in system!