Pistons have coolant ***help***
Blow out what you can from the top side. Pour a 1/2" of Sea Foam on top of the Pistons and let it sit for a couple of days. This will rinse the anti-freeze out of the ring grooves and run it down into the pan, leave the drain plug out and catch into an oil drain pan. This should show you the green anti-freeze that came out.
Also the Seafoam loosens up the Carbon Deposits around the rings and ring grooves, resulting in some pretty Black Oil coming out of the bottom of the oil pan. Rings will work better and better compression too. Pour another quart of new oil over the camshaft holes, this will run into the pan and out the drain plug helping to clean out the inside bottom of the oil pan.
Good To Go ! Have fun putting your engine back together, not to worry . . .