Toyota Repair: Coolant change on 99 Sienna, drain valves, coolant

Question
How many drain points are there when draining out coolant from a 99 sienna. Vehicle has a rear heater.

Answer
The best way to do this is to use a coolant flush machine, most dealers and repair shops have one, this will remove all of the old coolant without having to open the valves on the block, another way is to just drain the radiator, add water and run the engine with the heaters on and drain the radiator again,repeat as needed, this will get almost all of the old coolant out, there are drain valves on the block, I think one on each side but we never use them because draining them still doesn't remove all the old coolant.