undo bottom rad hose and let system drain....
put the hose back and fill the system with water and pour some coolant system cleaner in (or 1-2 tablets of false teeth cleaner) then replace cap on exansion tank,bleed the air out.... allow system to cool down in between topping up (since you have no antifreeze in it will boil quicker!)....
repeat the flush procedure 2-3x depending on how clear the water coming out it....
last time flush with water only, no additives....
then fill system with 50% G12++ or equivalent and 50% water.... bleed air out....
to bleed air efficiently leave cap ON and knead the radiator hoses with engine running, rev engine up occassionally to 2-3k rpm....
