What could possibly go wrong? It was $140 (which was ok by me) by the professionals, but they couldn't do it (they needed 2 hours). So far I'm out of pocket $65 (and I'll at least know what's gone in it, have a little left over for top-ups and get the chance to really clean that overflow bottle).
My thoughts are, drain, flush with tap water, fill with distilled, drive around till hot, drain again, fill with coolant and top up with remaining distilled.
Thoughts anyone?