I just drain the radiator, and refill it with water a few times. You can also use a flush if you want as well.

I don't want to mess with the block drains since by the looks of mine they will not only be a battle to remove, but make a nice mess in the process. You seem to be able to drain most of the system just from the radiator, plus if you do it every two years leaving a couple of quarts of the old stuff in their really isn't a problem.

__________________
2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200