Canon imagePRESS C7000VP Reference Manual page 524

4
Hold the staple case by its left and right sides, and lower
the bracket on the staple case.
5
Remove the jammed staples from the staple cartridge.
6
Return the bracket on the staple case to its original
position.
7
Gently push the staple case back into the saddle stitcher
unit until it is securely in place.
Clearing Staple Jams A8-105