Removing the Document Cover
For thick documents or other materials that are hard to scan, you can remove the document cover. To do this, hold the back of the document cover behind the hinge and lift straight up.
Do not force the cover off the scanner or lift from in front of the hinge. This may damage the cover.
Note:
When scanning with the cover removed, make sure you cover any exposed areas of the document table to prevent interference from external light.
Reattach the document cover by pushing straight down on the back of it until it clicks into place.