The ADF assembly will have to be removed first to get the flatbed scanner out. When you remove the ADF unit you not use the ADF cable that is attached to the unit to lift or move it. Once removed it should be placed on a flat level surface.
1). Turn the printer off and remove the power cord form the printer.
2). While facing the back of the printer you will see the ADF cable coming from the back of the ADF to the scanner control board. There are two screws that need to be removed on the cover to access the scanner control board. Once the cover is removed there is a grounding screw that must be removed. Now the two cables can be disconnected. Before removing the cable take note of the way the cable is routed through the cable holder into the scanner bed.
3). Open the ADF assembly like you were going to make a copy on the flatbed scanner and lift the ADF off of the scanner. The ADF assembly has been calibrated to work with the scanner on which it is installed. If you were to replace the ADF unit or install it on another flatbed scanner, that scanner will have to be calibrated to with that ADF.
4). Raise the scanner assembly to the up position. While facing the front of the printer, you can now remove the front edge flange. This piece runs across the top front of the flatbed and will just snap out.
5). Looking at the top left side of the flatbed, on the paper exit side remove the two screws that hold the scanner carriage lock cover.
6).Facing the rear of the printer, remove the screw on the far left which is the right side scanner cover.
7). Close the top cover and remove the two screws from the top which hold the left scanner cover in place. Use a magnetized screwdriver to avoid dropping these two screws. There is a spring located near the rear of this cover that is not captive. Take care not to lose the spring when removing the cover.
8). Now you will see a metal plate with a series of holes in it. There are three holes that are larger than the rest and that's where the three screws will need to be removed from.
9). Facing the rear of the printer, remove one FFC (flat flexible cable), and the connector to left of it on the scanner control board.
10). Facing the front of the printer, slide the scanner slightly to the right and then lift it up off of the printer. CAUTION: Make sure you do not release the scanner latch while the scanner assembly is removed. The gas shocks that support the scanner assembly can damage the sheet metal scanner assembly platform if the platform is raised when the scanner assembly is not installed.
When you are ready to reinstall the scanner be sure to align the mark on the scanner assembly with the mark on the control panel to correctly position the scanner assembly. With the scanner assembly correctly positioned on the sheet metal platform, slide the assembly toward the left side of the MFP until it locks into place.