as per chee's guide: http://www.perth-wrx.com/vb/diy-mechanical-modifications/10390-radiator-coolant-flush.html

"Step 4: Remove the thermostat housing and the thermostat." does this have a gasket? and if so I guess it would be recommended to replace it? can someone just clarify that for me pls, ive just dropped the coolant from the bottom hose connected to the thermostat..seems to have got it all out but yeh..wanna do it right obviously

also, I got this Tectaloy radiator flush..has anyone used this as it says drain..then fill backup with water only and the bottle for every 10litres of water which is 500ml...and run motor for 10mins minimum ...isnt this gonna overheat? maybe?