You have to request for free timed-entry passes via their website. Same-day passes are available for request starting at 6:30 AM. We woke up at 6:30 AM and easily got the 10:30 AM entry passes. You can only show up on or after the time you chose, otherwise you will be refused entry. You can stay for as long as you want after getting in. The guided tours are within the time frame and you can select, based on the times you pick.
They have video though the whole plae
Best to browse at your own pace. Exhibits are self-explanatory.
Thanks! Your answer is awaiting moderation.