Player 1: A simple introduction to the Excursion Funnels, you should simply place a portal on the ceiling panel above the excursion funnel and then peer over the edge to your right and fire your second portal on the right-hand wall panel, so it re-appears and moves from right to left.
Player 2: Jump down into the new funnel ahead of player 1 and set a portal on the wall in front of you and also on the single jutted-out wall panel up and to your left. This will carry both of you across to the red button on the wall. Once you reach here, stay still!
Player 1: Drop down onto the temporary extended floor below you and turn to your left to face the wall panel. Shoot this so the funnel is taking you straight through the doors and right to the exit! If you get your head stuck, duck down to make it through the doors. Player 2: Drop down into the Excursion Funnel below and follow player 1 right to the exit.