Canon DR-5010C - Manual (Page 15)

Before Using the Scanner 13
4.
Remove the protective sheet then the protective material securing the pickup
roller.
Pickup Roller
5.
Remove the roller cover, then remove the protective material securing the
retard roller. Replace the roller cover.
Roller Cover
Retard Roller
6.
Gently close the Upper unit. Be sure that the Upper unit is completely closed
by pushing on both edges with both hands until you hear a click.