Read all istructions before work on your model. Make sure you have all parts and supplies. Test-fit all parts together before applying any glue. If any parts don't fit properly, sand as required for precision assembly.
Produce the [case_bottom] with the [3d_printer]
Produce the [case_top] with the [3d_printer]
Put the [arduino] into the [case_bottom]
Put the [case_top] on top of [case_bottom] and mount it with the [screws]