Place the high chair on a flat surface where it will not tip over or move on its own. When the high chair is secure, lift your child up under her arms and gently sit her in the chair so that she is centered. The middle strap should be directly between her legs.
Connect both buckles from the side straps to the connector on the crotch strap until they click into place. Give them a firm tug to ensure they are latched. Pull on the excess length of each strap to remove the slack. There should be enough room between your child and the straps for you to stick a finger between.
Grab the main tray from underneath and pull toward you. The tray will move upward and into position at the child's midsection. Press on the handle on the front of the tray to unlock it, allowing you to slide it backward or forward to give your child more room. You can also remove it by pulling forward.
Push down on the tabs on either side of the top of the tray to remove the insert. This allows you to take the insert to the kitchen for use as a tray for your baby's food. Place the insert back into the main tray by pressing downward until it locks into place.
Grab the handle from the main tray and pull down to return it to its storage position. Press the button on the middle of the crotch strap and move the straps to the side. You can now safely lift your child from the high chair.