Do you have to squeeze the lungs push air out?

The lungs do not have to squeeze to push the air out.

When we inhale, the diaphragm contracts and the intercostal muscles between the ribs contract. This increases the volume of the thoracic cavity and air is sucked into the lungs. When we exhale, the diaphragm relaxes and the intercostal muscles relax. This decreases the volume of the thoracic cavity and air is pushed out of the lungs.