Removing The Document Cover; Reattaching The Document Cover - Epson Perfection 636 Reference Manual

Removing the Document Cover

If you're scanning something that doesn't fit under the document cover,
you can remove it. To do this, simply lift the back of the document cover
straight up.
When scanning with the cover removed, make sure you cover any
exposed areas of the document table glass to prevent interference from
external light.

Reattaching the Document Cover

When reattaching the document cover, be sure to hold the cover in a
vertical position as you push its attachments into place.
Installing the Optional Equipment Page 40