HP Color LaserJet Enterprise Flow M776z All-In-One Laser Printer - Manual (Page 265)

13. If paper is jammed as it enters the output bin,
gently pull the paper out to remove it.
14. Close the jam-access door on the fuser, and push
the fuser completely into the printer until it clicks
into place.
15. Close the right door.
ENWW Clear paper jams 251