you could empty your radiator, then fill with water mixed with a flushing agent, then drain and fill up as normal.
there is a drain plug on passenger side of the radiator, undo that (or the bottom hose)
fill the rad to the top with your water/coolant mix.
then start the car with the heater on.
let it run for a while and the coolant level will drop, keep filling it up as it drops...
once the car is up to temp. put the cap on the radiator, and then bleed the system further using the bleed point at the front of the plenum. 12mm bolt with a heta warning sticker.
open that and let the bubbles come out, once no more bubbles come out, tighten it up and away you go.