Toyota 2012 Yaris Hatchback Owner's Manual page 88

1-7. Safety information
Forward facing ⎯ Convertible seat
■
Remove the head restraint. (→P. 51)
106
Place the child restraint system
on the seat facing the front of the
vehicle.
Run the seat belt through the
child restraint system and insert
the plate into the buckle. Make
sure that the belt is not twisted.
Fully extend the shoulder belt
and allow it to retract to put it in
lock mode. In lock mode, the belt
cannot be extended.