Brother DR-500 Drum Unit - How do I clear the message Dust on Drum?

Dust or toner on the corona wire may cause this message to appear on thedisplay. To clean the corona wire, follow the instructions listed below.

1. Turn off the power switch and unplug the power cord.
2. Press the cover release button and then open the front cover.
3. Remove the drum and toner cartridge assembly.
Note : We recommend that you place the toner and drum assembly on a piece of paper in case you accidentally spill or scatter toner.
4. Clean the primary corona wire inside the drum unit by gently sliding the blue tab from right to left and left to right several times. Return the blue tab and snap it into the home position before you put the drum/toner assembly back into the machine. If you don't, printed pages may have a vertical stripe.
5. Reinstall the drum and toner cartridge assembly back in the Brother machine.
6. Close the front cover.

If the problem continues the drum (DR500) must be replaced.