Brother DCP-9055CDN Basic User's Manual page 50

IMPORTANT
Put the toner cartridge in the drum unit
immediately after you have removed the
protective cover. To prevent any
degradation to the print quality, DO NOT
touch the shaded parts shown in the
illustrations.
k
Hold the handle of the toner cartridge
and slide the toner cartridge into the
drum unit then slightly pull it toward you
until you hear it click into place. Make
sure that you match the toner cartridge
color to the same color label on the drum
unit. Repeat this for all the toner
cartridges.
42
C
M
Y
K
C - Cyan M - Magenta
Y - Yellow K - Black