If you are going to do it yourself, drain the radiator and remove the block drain plug(s). Also remove the thermostat. Run fresh water through the cooling system until it runs clear. Replace the block plugs and radiator drain plug and refill with coolant. Also make sure the heater is set to maximun heat (to clean the heater core).
This is a messy business, and coolant is toxic and hard to clean up.
You may want to look at the cost to flush the system at a local garage, in many cases you can get it done for under $150.
Tuesday, November 17th, 2020 AT 10:19 AM