To navigate the interface:
If you'd like to adjust the parts to your liking, Tyler from SlicePrintRoleplay Youtube Channel has an awesome tutorial on how to do this in Meshmixer quick and easy! Tutorial available here: https://youtu.be/sJiyUvsUvt8
Important notice - this customizer is mainly for preview purposes of 3d printable pre-supported bits, so some parts may clip and overlap in the 3d view, while they will actually work fine on an print assembled from bits.
If you find bugs, errors or issues, or have general quality-of-life improvement ideas for the Customizer, please send me a message at: firstname.lastname@example.org or via the Facebook Fanpage.