- Remove the toner supply unit inner cover. (Toner Supply Unit Inner Cover)
 Remove the sub hopper unit [A].
e.g.: Y- For the following models and colors, the toner fall prevention sheet is attached to the toner supply unit side.
- Pro C5200S/C5210S: K, C
 - MP C6503/C8003: K
 
 - When installing the sub hopper unit [A], take care not to tuck the toner fall prevention sheet [B]. The following picture shows the normal state.
e.g.:C 
- For the following models and colors, the toner fall prevention sheet is attached to the toner supply unit side.