Cashbox handling is described in the following steps.
Removal:
Insert the main key & rotate it clockwise 45 degrees.
The key only rotates in a single direction, and only 45 degrees (1/8 of a turn).
Eject the cashbox by pushing back the nearby release tab.
Do not force the tab further after the cashbox has begun to eject.
To re-insert the cashbox, you MUST open the cashbox first!
Reinsertion:
Slide the closed cashbox fully into the empty slot,
Rotate & remove the key.