Lexus 2003 LS Owner's Manual page 174

COMFORT ADJUSTMENT
16L315
4. To remove the infant seat, press the buckle–release button
and allow the belt to retract completely. The belt will move
freely again and be ready to work for an adult or older child
passenger.
160
(B) Convertible seat installation
16L307
A convertible seat is used in forward–facing or rear–facing
position depending on the age and size of the child. When
installing, follow the manufacturer's instructions about the
appropriate age and size of the child as well as directions for
installing the child restraint system.