For outer positions: Raise the outer head restraint to its highest position, then route the tether strap between the head restraint legs. Make sure the strap is not twisted.
For the center position: Raise the center head restraint to its highest position, then route the tether strap between the head restraint legs. Make sure the strap is not twisted.
Always use a tether for forward facing child seats when using the seat belt or lower anchors.