Printing this model is a challenge due to severe overhangs. In particular, if you print the skull upright almost the entire bottom surface has no support. Unless you have a machine that can provide support, printing it probably won't be pretty.
To address this problem, we decided to print the skull in two parts: a top and bottom. The bottom part is flipped so that the cut plane becomes the bottom layer, and the top part remains upright. Since the skull is hollow each part is basically a hemisphere. This configuration is still a challenge to print, and will likely have some problems at the top. Fortunately, the defects will be on the interior of the model.
There are still a number of smaller overhangs with this configuration, but we found that they can be cleaned so that they become largely unnoticeable.