Brother DCP-L8400CDN Basic User's Manual page 72

j
Turn the blue lock lever (1) clockwise to
the lock position.
k
Push the drum unit in until it stops.
64
l
m
1
Close the front cover of the machine.
When you replace the drum unit with a
new one, you must reset the drum
counter. Instructions of how to do this
can be found in the box your new drum
unit came in.