Canon LBP6780x Manual page 881

8
Holding the green tab (B) at the front, lift the transfer guide at the front.
Do not take your hands off the transfer guide until it moves back to its original position in Step 10.
9
Remove the paper by pulling it gently.
Remove the jammed paper as horizontally as possible to prevent unfixed toner from spilling.
10
Move the transfer guide back to its original position slowly.
11
Install the toner cartridge.
Push the toner cartridge into the printer firmly until it touches the back of the printer while aligning (A) on both sides of the
toner cartridge with the toner cartridge guides inside the printer.