I'd like to start by saying that I enjoyed your tutorial w/ great pic.'s James, and learned from it. And you are right about a few more steps w/ the SRT. Although the engine coolant and IC/HE coolant circuit share the same surge/fill reservoir, they are 2 separate systems. You hear about many of us SRT owners separating the 2 systems; but we're merely disconnecting(separating) the overflow line that comes from the IC/HE circuit. Some just cap or valve it off, and others add another small fill/spit tank to run it through. This eliminates the heat transfer between the hotter running engine coolant and the much cooler(after separating) IC circuit. I'm getting off track here; to drain the IC/HE you need to open up that system. When I did this, I was installing a new IC pump and upgrading to a larger HE, so all the lines were open to drain. The stock HE has a drain petcock on it, but it was on the top of mine!? You have to remove the HE from its perch and drop down to open and drain. Or you can remove the coolant lines from both sides of the IC pump to drain. I haven't tried the compressed air method that Woody suggested, but the circuit still needs to be opened to flush out one way or another.

And to Billy22Bob; You are confusing the SC with the IC/HE. If you drained the SC, you would have one major stinking mess on your hands. That though, is also information you could get by using our search engine here.