Leave Al's RoboShack through the rear exit and use your new Heli-Pack's boost jump (crouch with , followed by jumping with ) to climb the nearby cargo. At the top, perform a stretch jump (same controls as a boost jump, except you must both crouch and jump while running forwards) to reach the elevator platform up ahead. At the top, you must then glide (holding in mid-air) to safely land on the area below and to the left, on which you will run into a trio of blarg commanders. Take the elevator behind them to the top of another tower.
Now you will encounter a small group of robomutts, a lone mine layer, and a blarg generator that will produce more robomutts. Regardless, none of these are a real threat and will go down quickly under continuous fire from any available weapon. Go along the bridge and up the escalator to reach a train station, guarded by several more commanders. Take note of a rather large amount of crates hidden behind stacks of cargo on the left before boarding the nearby robot train and automatically transitioning into the mission "Ride the Robot Train".