Most D/B series I have seen have the coolant drainage plug located on the front of the block to the left of the exhaust manifold. IMO it's not worth the effort to remove this just to drain... I did it once, and vowed never again after all the hassle.... Not sure where K-series is located if you have EP3 as per your sig.

Just flush with plenty of distilled water. FYI you can buy distilled water from Coles.

5L for about $3. So $20 would easily completely flush the system. It's down the ironing isle.