* Know a SpaceX employee very well - they can give a tour of the main building but most are limited to two tours per year. I am sure their families and closed friends have priority.
* Work for a SpaceX supplier-be in a position where you need to have a meeting with SpaceX employees on site.
* Buy a Falcon 9 launch, or at least try to negotiate.
* Attempt to buy a tourist seat on the BFR and make sure they believe you have the money.
* Apply for a job there, and you need to pass at least 3 or 4 rounds of phone interviews and on-site interviews. If you are not in the top 10% of your field, forget about it. https://www.quora.com/How-can-I-get-a-tour-of-SpaceX