Avery Dennison Monarch 9855 Operator's Handbook Manual page 30

Make sure the printer is configured for the correct supply type.
1. Open the cover.
2. Unlock the printhead by turning the retaining latch.
3. Lift printhead assembly using the printhead tab until the assembly locks
into place.
4. Shake the roll of string tags down to untangle the roll.
5. Place the roll of supply on the supply holder with the strings facing out.
2-14 Operator's Handbook