The only thing I changed from the "Master Ball, with magnetic clasp" was the lid again.
Print the Lid.stl file and print two copies of the Lid_Arch.stl file, they won't need supports. After printing the parts you should be able to easily assemble the lid. (Please note that the arches only fit in one way, so if it isn't fitting quite right flip it upside down) From there glue the button into the button holder. Then glue the button assembly and the ring to the bottom with the hinge in place as you glue the ring down. Then snap the hinge into the lid.
You will need 2 magnets (1/4" X 1/16") and just glue them in place.
Tip: Print your bottom piece at a higher in fill percentage, around 40-50% and then all the other parts at 5-10%. That way it will be bottom heavy and not roll around as much.