Oki CX2731 User Manual page 217

c) Hold the blue handles of the new image drum unit and place it
into the machine.
d) Unpack the replacement toner cartridges, and gently shake
each one up and down, and from side to side (1 is black, 2 is
the other colors).
217
Replacing Consumables
–
CX2731 MFP Basic User's Guide