For a mfc2700dw:
Remove the drum unit and toner cartridge assembly.
Press the green tab to eject toner.
Take the cover off of the new toner cartridge.
Install the new toner cartridge in the drum unit correctly.
Reinstall the toner cartridge and drum unit assembly in the machine.
If the problem continues, replace the toner cartridge.
For a mfc2710dw:
Open the front cover
Remove the drum and toner assembly and place it on a flat surface
Press the green lock lever to remove the toner cartridge from the drum unit
Unpack the new toner cartridge and remove the protective cover
Insert the new toner cartridge into the drum unit until it locks into place
Reinstall the drum and toner assembly into the machine
Close the front cover
For a mfc2550dw:
Ensure the printer is on
Open the front cover
Remove the toner cartridge and drum unit assembly
Press down the green lever to separate the toner cartridge from the drum unit
Unpack the new toner cartridge and remove the protective cover
Push the new toner cartridge into the drum unit until it clicks into place
Clean the corona wire by sliding the green tab back and forth several times
Reinstall the toner cartridge and drum unit assembly into the printer
Close the front cover