Canon NP6551 Operator's Manual page 181

Open the left feeder cover completely, and
2
remove any jammed originals.
After removing all jammed originals, close the
right feeder cover.
Open the feeder.
3
Open the cover located on the bottom-right side
4
of the RDF, and remove any jammed originals.
MEMO: ●
If the original is difficult to remove, then as shown in
step 2, open the right feeder cover again and
remove the jammed original.
If there is an original on the platen glass,
5
remove it.
Close the feeder.
6
MEMO: ●
Occasionally the paper jam message may remain in
the display. If this happens, follow the directions in
the display and check again for any jammed paper.
6-7