2. Test it a bunch (boring, but not hard)
3. Fly it (practice makes perfect)
4. Bolt a tin can to the top of it and pressurize it so the humans don't die (but don't make it do anything else except that)
5. Head for the moon (Just Do It)
6. Make sure to take a tent and some food, it's cold
Caveat: DO NOT become involved with NASA Systems Engineering process because this will be like being stuck in a tar pit. NOTHING will ever get done, the meetings will stretch out forever, and then Congress will pull the plug.
Hint: Musk is pretty much done with steps 1 thru 4. I can safely tell you he's hot on the trail of 5 and 6.