Open the front cover.

finisher(4K)-cover_close.jpg
Squeeze the green parts of the staple case and pull the case up and then out.

finisher(4K)_staple-case_out.jpg
Lower the lever at the front end of the staple case and remove the jammed staple.
Remove the leading staple if it is bent. If bent staples remain, a staple jam will occur again.

S-finisher_staple-lever_up.jpg

staple-break.jpg
Take care that a bent staple does not hurt you.
Return the lever to its original position.

S-finisher_staple-lever_down.jpg
Push the staple case firmly back in.
Push the staple case in until it clicks into place.

finisher(4K)_staple-case_insert.jpg
Close the front cover.

finisher(4K)-cover_close.jpg
Make a proof copy in staple sort function to verify that stapling takes place correctly.