Inside a crevasse on Mt. Rainier’s Nisqually Glacier

My BCC (Basic Climbing Class) team lowers me into a small crevasse on the Nisqually Glacier on Mt. Rainier to practice the “z-pully“, a method of crevasse rescue. Scenario: Three people are traveling on a rope across a glacier. The lead climber falls through a snow/ice bridge into a crevasse. How do the other two climbers pull the lead climber out?