HP Color LaserJet Enterprise CM4540 MFP series - Manual (Page 315)

2. Lift the green tab on the staple cartridge up,
and then pull the staple cartridge straight out.
3. Lift up on the small lever at the back of the
staple cartridge.
4. Remove the jammed staples.
5. Close the lever at the back of the staple
cartridge. Be sure that it snaps into place.
ENWW Paper feeds incorrectly or becomes jammed 295