what do you suggest the type of flush and how many times to do this.

well to do a flcuh you can either take it to a local oil change shop and they can do it. but you can also go to autozone or some place and buy a fluch kit, where you put in inline to the radiator lines and its a t-handle looking thing, that you hook up the gardenhose to then it flushes everything out of the cooling sytem, then you just have to refill with 50/50 mix.