How to refill sharp 168d

First open the right-side door, then depress the upper side tabs of the front door to open it.

The toner bottle has a green, square plastic thumb grip on the top, front part of the bottle. Press down on this part as you pull forward. You should be able to remove the bottle and replace it. Make sure the new toner bottle fully seats before closing the unit up.

Close the front door, then the right-side door and the machine should recognize the new cartridge.

If you're looking to have the bottle re-filled, you will need to contact one of the third-party companies that refills and sells toner bottles. I would advise purchasing a new, authentic bottle of Sharp toner for this unit, as re-filled, non-Sharp toner providers have a history of selling poor quality toner refill kits.