orange coolant

[Will UK]

Hi all. Planing to flush my coolant because its not pink colour anymore, looks like red inside expansion tank, but when i replaced my cts last week, coolant that escaped looked contaminated.



bought 3l of g13 + new thermostat from dealers.




i've been reading alot about coolant flush, Mr,haynes, Elsawin...still a bit confused. should i just remove bottom radiator hose + oil cooler hoses and drain it all? fill it with fresh g13/water with the hoses secured. some people say that i should drain radiator first, removed thermostat ,fill the system with water and drive the vehicle for 10 mins and drain the lot again? is this how you do it? dont want to bodge it

any help appreciated
thanks