Here you are… Obviously you need to supply your own ISO.
We basically run Stage 2 and 3 as a Policy (we have a preset in Stage 2). This way folks via the Web Console can easily deploy Stage 1 and all others are automated.
Note that Stage 2 command line does NOT include the /noreboot switch (as this causes a failure in the upgrade and creates a new ID for the endpoint). Be sure your Stage 2 verbiage makes note of that to the user.
Also note that 1803 will break IBM ClearCase 8.x and 9.x, so there is relevance that excludes those from Stage 1 and 2.