Epson Action Laser - Manual (Page 124)

Maintenance Messages
11.
12.
Note: Be careful not to get any dust or dirt into the exposed
developer unit.
Holding the new replacement toner cartridge horizontally,
gently shake it back and forth a few times to distribute the toner.
Hold the toner cartridge over the developer unit so that the label
is facing up, with the top of the label pointed toward the inside
of the basket. Align the four hooks on the cartridge with the slots
in the developer unit and set the cartridge onto the developer
unit.
6-8 Maintenance and Transportation