How do I convert the Evenflo Pivot to booster seat mode?

To convert to high-back booster mode, loosen the harness straps by pushing the harness release button and unfasten the chest clip and buckle. Remove the crotch buckle from the slot, remove the seat base from the booster back, and store the crotch buckle. Lift the headrest pad, disconnect hook-and-loop connectors, push shoulder straps behind the headrest pad, and pull harness straps and chest clip through the forward-facing belt guides. Snap the chest clip together behind the seat and adjust the booster to the upright position. (Pages 56-57)