HP LaserJet 3055 - Manual (Page 265)

Load staples
Each staple cassette holds 1,500 unformed staples. To load staples into the all-in-one, insert a staple
cassette.
To load staples
1. Open the stapler door.
NOTE Opening the stapler door disables the stapler.
2. If you are replacing a staple cassette (for example, if your staple cassette has run out of
staples), remove the staple cassette from the all-in-one.
3. Insert one 1,500-staple cassette into the opening inside the staple door.
ENWW Other: How do I? 247