1. Install the base Place the base in the center of the backseat and thread the seat belt through the guides. Kneel on the base as you tighten the belt; make sure the base cannot move more than 1 inch in any direction.
2. Put the baby in the seat Place your child in the car seat and secure the harness; make sure the harness is snug against your baby’s hips and shoulders. Adjust the chest clip so it’s level with your baby’s armpits.
3. Put the seat in the car Place the car seat in the base, making sure it snaps in securely. Flip the handle down and lock it into place; this will prevent it from harming your baby in case of an accident.
4. Check the angle The seat must be installed at an angle that keeps your baby in a semi-reclined position; his head must not be able to flop forward. Place a rolled-up towel under the base to get the right angle, if needed.