Push on the tab to secure the scanner harness holder to the scanner cover.

De-route the document detection/document scanning position sensor harness and the ADF motor harness from the scanner harness holder.

During reassembly, put a 20mm-thick pad (book, stack of paper) on the scanner glass, close the scanner cover, then route the document detection/document scanning position sensor harness and the ADF motor harness through the harness holder. This will ensure the proper harness tension to allow scanning of thick books.