Simply search @Xulfiqar method of flushing radiator and buy yourself these tartri and other stuff. Keep 6 Litre empty water bottles and use home rough Tub for collecting old drained liquid.
Keep in mind whenever I did on my car and even other pakwheelers do it with me , Almost all of the time we resulted into blown gasket after that but we are satisfied at least that we have cleaned scaled up corrosion. For this, keep that future expense and Mechanic trip in mind too. 10% home made Acidic solution is far better than market available products