GMC Yukon Denalid Owner's Manual page 82

82
If the position you are
using does not have a
head rest/restraint
and you are using a
dual tether, route
the tether over the
seatback.
If the position you are
using has an adjustable
head rest/restraint
and you are using a
dual tether, route
the tether around the
head rest/restraint.
3. Push and pull the child restraint in different
directions to be sure it is secure.
If the position you are
using has an adjustable
head rest/restraint
and you are using a
single tether, raise the
head rest/restraint
and route the tether
under the head
rest/restraint and in
between the head
rest/restraint posts.