Head Gasket issue

[Keitai]

Undo the clip holding the bottom hose onto the radiator and gently pull the hose clear.
Have the expansion bottle cap off and the heater control on hot.
Let the water run out, flush through the expansion bottle with a hose until the water seems clean enough.
Reconnect the bottom hose, fill the system up and run the engine with the bottle cap off for a while until the air is purged. There may be a tyre type valve cap somewhere for bleeding so slacken that.
Check the heater works!
This won’t flush everything out but it will do for now.
John

Ok thxs. Bit clueless on vehicles tbh.

I haven't changed the water yet

Just got mechanic to check if more oil in header tank with the old water. He couldn't see any. I guess all is good. Still recommended steal seal if any tiny leaks though. Wondering whether to bother or just carry as is and monitor it myself