Canon iR6570 series Service Manual page 338

Chapter 8
[1]
3) Remove the 2 jam removal levers [1] of the duplexing feed unit; then,
remove the 3 screws [2], and detach the duplexing feed front cover
[3].
[2]
[2]
[1]
4) While pushing the hook shaft [1] found at the rear of the fixing feed
unit in the direction of the arrow (i.e., toward the machine's front),
turn the fixing feed unit releasing lever [2] clockwise to lock it in
place.
8-74
[2]
F-8-231
[3]
[2]
F-8-232
[2]
5) While pushing the 2 stopper plates [1] of the rail assembly of the
fixing feed unit toward the inside, slide out the fixing feed unit [2] to
the front.
[1]
F-8-233