I don't recommend going to this museum during the summer. I just went to it last week & I was sweating head to toe by the end of it. They are planning to offer a night tour in the near future so you can look into that. If you do choose to go during the summer heat, bring an umbrella, fan, & big jug of water. If you forget any of that they have it all their for sale & rent.
Whenever you go keep in mind it's only by tour. Either call or schedule it online. They only have a capacity of 6-8 on a tour. Locals, students, & seniors all get discounts so make sure you bring your IDs.
The whole tour takes about 45-60 minutes. The tour guides are very knowledgeable. There is little to no shade on the tour. If you're a picture taker like me hang at the back of the tour to get pix w/o people in them. Very informative & cool. Caddy corner to the museum there is another section full of signs that have yet to be displayed. No touching or climbing on the signs for all those trying to create the super cool pix.
It's worth checking out if you're a local or a tourist to mix things up.