Brother HL-4040CDN - Manual (Page 110)

Routine Maintenance
101
6
a
Turn off the printer power switch. Press the front cover release button and then open the front cover.
b
Hold the green handle of the drum unit. Lift the drum unit up and then pull it out until it stops.
c
Hold the handle of the toner cartridge and pull it out of the drum unit. Repeat this for all the toner
cartridges.