Canon SCANFRONT 300P - Manual (Page 168)

9-7
Chapter 9 Maintenance
3. Move the feed roller in the direction of the arrow a,
and then remove it from the shaft b.
4. Remove any dirt from the roller using a cloth that has
been soaked in water and thoroughly wrung out.
5. Align the notch in the shaft of the roller with the shaft
of the scanner, and place the feed roller into position.
6. Move the roller lock lever in the direction of the arrow,
and then insert it into the hole in the feed roller.
7. Lower the roller lock lever to lock the feed roller into
position.
8. Close the roller cover. Make sure that you hear a
click, which indicates the cover has returned to its
original position.