Canon MF55DD Series Basic Manual page 110

2
Widen the slide guides until they stop, and remove the paper so
as not to be caught by the slide guides. Open the ADF and gently
remove the jammed paper from the ADF.
3
Open the ADF and gently remove the jammed paper from the
document output tray.
NOTE
After removing jammed paper, even edges of the document before loading it in the ADF
9
again.
9-8 Clearing Jams