HP 3550 - Manual (Page 133)

5. Place your thumbs on the blue ridges (near the warning label) and, using fingers, pull up
on the blue latches.
6. Pull the fuser out of the printer.
NOTE For information on how to properly dispose of the used fuser, go to http://www.hp.com/recycle .
7. Remove the new fuser from the bag.
ENWW Replacing supplies and parts 121