Brother HL 4150CDN - Manual (Page 142)

Routine Maintenance
136
5
j
Put a piece of paper (A4 or letter) on the belt unit to prevent damage to the belt unit.
k
Make sure the green lock lever (1) is in the release position as shown in the illustration.
l Match the guide ends (2) of the drum unit to the c marks (1) on both sides of the machine, then gently
slide the drum unit into the machine until it stops at the green lock lever.
1
1
2