Check the car seat manual for the correct strap adjustment method
Locate the harness adjuster strap or release button
Press and hold the harness release button if your seat has one
Pull the shoulder straps outward to loosen the harness
Lift the harness adjuster lever if your seat uses a lever-style release
Pull the straps forward while holding the release mechanism
Loosen the crotch buckle area if needed according to the manual
Reposition the child, then re-tighten the straps to the proper fit
Ensure the straps are not twisted after loosening
Confirm the harness still meets the seat’s safety requirements