You understand this pretty well.
What is valve lash? Once you have the engine/crank-shaft so the #1 cylinder is at TDC (both the #1 inlet and exhaust valves are open/loose-lash) now you can do a "cold setting" of half of your valves.
Then rotate the engine/crank-shaft 360 degrees until the #6 cylinder is at TDC. Then do a "cold setting" of the other half of the valves. Some people just set/adjust the cold engine valve lash to the "normal" settings rather than the cold settings (instead of adding 0.005" to the normal setting).
Start the engine and after its temperature settles, run it for another 30 minutes. Then reset the valve lash of all valves (using the normal/hot settings).
Good luck. Let us know how this works out for you.
