Brother MFC-8440 B - Manual (Page 191)

TROUBLESHOOTING AND ROUTINE MAINTENANCE 12 - 30
2
Hold down the lock lever on the right and pull the toner cartridge
out of the drum unit.
Caution
Handle the toner cartridge carefully. If toner scatters on your hands
or clothes, immediately wipe it off or wash it with cold water.
Lock Lever