@Al Steel
Alright apologies for the delay, coolant change has been done for a month but I have had almost no free time lately so I'm just getting around to posting. This should take you about 45 min - 1.5 hours, and will probably make a bit of a mess, so try to do this in a place where you can clean up any spilled fluid without it running off into a storm drain. This stuff ain't great for the environment lol.
To do this you will need 2-3 gallons of the Ford Gold antifreeze/coolant (VC-7-B), a quart of Motorcraft VC-1 coolant flush fluid, the same surgical tubing as before, a bucket or two, containers for disposal, ready access to a hose, and some distilled water (optional, but only a few dollars worth is needed).
Once you have everything ready, the first thing I did was a pre-flush. Remove the cap to the coolant reservoir, and locate the drain plug to the radiator. It will be on the bottom corner of the radiator on the passenger side, and the only way to access it is from underneath. There should be a nozzle that will perfectly fit the same diameter tubing I used in the power steering flush above. From the underside it should look like this:
That little white hex shape is the release. Attach the tubing then turn gently, if you apply a lot of force you can round off the "bolt" as it is made out of plastic. During the pre-flush it helps if the engine is cool. If you are doing this with a warm engine be very careful as it will be very hot.
Now open the drain plug and let all of the coolant drain. It should take about 5-10 min. While it is draining flush it out with a hose spraying into the coolant reservoir, making sure no large amounts of air get into the coolant system. If you use the jet setting on your hose you can knock loose any of the built up gunk in the reservoir. Keep flushing until the fluid coming out of the hose runs clear. Then stop filling with the hose, drain the reservoir almost to the bottom, and close the drain plug. Keep the tubing attached. Add your VC-1 fluid to the reservoir, and fill the rest of the way with water.
Now we need to agitate the cleaning solution and make sure it does its job. Double check that the drain plug is closed, the water/flush mixture is filled between the min/max operating levels, and that the reservoir cap is on. Hop in the cab and start the engine to bring the coolant up to temp. To make sure the coolant will flush through the entire system, make sure your heater is on full blast in both the front and rear climate zones. After the engine has come to temp, make sure HOT air is blowing out of all of your vents. If any are blowing cool air there may be a blockage or leak in your coolant system, or one of the actuators that opens/closes the valves may be bad, or there could be air in your coolant system. Run the engine for 10-15 min, revving it frequently to really get the coolant moving. I kept it around 2k RPM and would rev it to 3-4k every 15-20 seconds or so.
Now comes the slightly more tricky part, a friend would come in handy here but you can do it yourself as I did. Shut off the engine and let it cool for about 5 minutes, just enough that you can SLOWLY open the cap to the coolant reservoir without it blowing up in your face. Be very careful when doing this as it will be under pressure. Make sure your tubing is still attached to the drain plug, and open it up. Have a friend add water from the hose slowly, or figure out a way to keep the hose on and in one spot so no air gets in the system. Start up the engine again while constantly adding and draining water from the system. Do this for a few minutes with the engine idling to completely flush out the VC-1 fluid.
It helps if you premix your distilled water/coolant before flushing out the cleaning fluid so you aren't trying to mess about with fluids while monitoring the draining/adding of water.
The system has a ~6 gallon capacity, so I used about 2.5 gallons of the concentrated coolant and 3 gallons of distilled water. The first gallon of coolant I added directly into the reservoir without premixing with the engine still running. Then keep adding a mix of 50/50 coolant/distilled water, and monitor the tubing and close the drain screw once you see the coolant you just added start to drain.
And that's it! Top off the reservoir, make sure the plug is screwed tight, but not too tight, and take it for a test drive with the heater in all zones on full blast. Make sure heat is coming from every vent. Once the test drive is done, let the engine cool and add or drain a bit of coolant if necessary to get it to the proper operating level.
As always feel free to PM me if you have any questions! Also, fordtechmakuloco has a solid video on this process on YouTube.
. Refilled with distilled and Prestone flush. Drove around for about 30mins, drained. Clear went in, brown water came out. 
I was going to do a second flush round but not enough time. Refilled with Prestone All-Vehicle and distilled to 50/50. Looks MUCH better now and at least I can read the level on the bottle. I KNOW I ran tap water in it, but I drained it, topped with distilled and the flush, then drained it again. Pretty confident it's either all out, or so little remained that it wouldn't create a problem.
