Brother MFC-9420CN Service Manual page 113

(37) Remove the one bind B M4x12 taptite screw from the document cover sub ASSY.
(38) Open the ADF unit and then release the hook to remove the document cover ASSY.
Hook
Taptite, bind B M4x12
(39) Move the spring as shown in the figure below.
(40) Remove the pressure roller ASSY.
Hinge
Fig. 5-37
Spring
Fig. 5-38
5 -2 6
Document cover ASSY
ADF unit
Pressure roller ASSY
Confidential