Canon DR-5010C - Manual (Page 49)

Using the Scanner 47
Installing the Document Eject Guide
When scanning a document that is particularly thin or particularly long, it
could droop down over the edge of the Document Eject Tray Extension and
become jammed in the scanner. Avoid this problem by attaching the
Document Eject Guide.
1.
Open the Document Eject Tray Extention toward you.
2.
Attach the Document Eject Guide in the order
➀, ➁ as shown.
3.
Press the Document Eject Guide to attach it to Document Eject Tray Extention.