Fujitsu M4099D Reference Manual page 48

Put the guide plate in position.
While holding the ADF sheet
guide assembly up, pull the ADF
release lever toward you then
gently lower the ADF sheet guide
assembly. Release the ADF
release lever to lock the ADF
sheet guide assembly into
position.
CAUTION
Hold the ADF sheet guide assembly during
this process to avoid damage to the sensors.
Close the upper transport unit.
ADF release levers
3-13