Open the front cover.

   Remove all of the toner cartridges from the printer.

   Pull the imaging unit out of the printer using the handle on its bottom.

   Extend the top handle on the imaging unit and then use it to pull the imaging unit out of the printer completely.

   Holding the handles on the new imaging unit, push the unit into the printer.

   Insert the toner cartridges into their corresponding slots until they click into place.

   Close the front cover firmly

   Turn the printer on.

It will take a few minutes until the printer gets ready after the toner self-distribution.