Location: The Library
Reward: The Spud gun
Ask the nerds about Earnest's whereabouts. Pummel them for information.
Jump over the gates. Along the path, the nerds are firing bottle rockets. Oohh, a new item! Take their Spud Gun once they're down.
Earnest and the Spud Cannon
Before you can enter through the guarded gate, Earnest, using the Spud Cannon, will do his best to stop your advances. The Spud Cannon hits hard and comes out in rapid bursts. Take cover behind the boulder, the pillars.
If you take a hit, there are a couple cans of Beam Cola around.
Here's your attack plan. Advance to the front, while using the pillars and rocks as cover. At the front of the gate, run to the right, to the corner. From the corner, the Spud Cannon can't reach you. It's basic geometry: the angle of the gun's trajectory can't reach you if you're directly below it...and it helps when there is a pillar in the path of the gun, which blocks the spuds. Using your Spud gun, aim at the transformer from FPS view.Same deal as before. Your goal is to destroy the two panels alongside Earnest.
Head to the front. Hide behind a pillar, then run to the front when Earnest pauses his shooting spree. At the front, behind a pillar, select your slingshot and go into FPS mode. It takes three shots to destroy a panel.
Instead of using his canon, Earnest will throw a pack of firecrackers, which has an insane blast radius. The key to survival is to get outside of the blast radius.
Facing the Spud Cannon, go the outer left, where you'll be outside of his blast radius. Here, you'll circumvent all explosions. Standing here, use your slingshot to shoot down the panels.
Hide to the right, behind the farthest pillar from the cannon. Here, you can shoot -- while standing -- the panels, without fear of the spuds hitting you. Look at the screenshot below for further explanations.