Step 1: Confirm that you have purchased a new genuine Brother Drum unit.
Step 2: Do not reset the drum counter when you only replace the toner cartridge.
Step 3: Press the front cover release button and then open the front cover.
Step 4: Press and hold down the Go button for about 4 seconds until all the LEDs light up. Once all four LEDs are lit, release the Go button.
Step 5: Take out the drum unit and toner cartridge assembly.We recommend that you put the drum unit and toner cartridge assembly on a piece of disposable paper or cloth in case they accidentally spill or scatter toner.
Step 6: Push down the blue lock lever and take the toner cartridge out of the drum unit.
Step 7: Unpack the new drum unit.
Step 8: Put the toner cartridge firmly into the new drum unit until you hear it lock into place. If you put the cartridge in properly, the blue lock lever will lift automatically.
Step 9: Put the drum unit and toner cartridge assembly back in the printer.
Step 10: Close the front cover.
Step 11: Make sure that the Drum LED is now off.
Step 12: Do a test print to ensure it is printing.