Max realizes when they try and retaliate, he will be gone. At the same time, he is trying to save the animal shelter across the street from his school which Principal Jindrake wants to destroy in order to build a football stadium. The football team is notoriously bad and the principal's primary motive in wanting to build the stadium is to brown-nose to Superintendent Knebworth (Clifton Davis), who was a football champion.
Max starts his revenge by stealing the coil of the Ice Cream Man's cooler which melts into Ice Cream Soup. Then he torments Troy McGinty in the MacGoogle the Frog costume, mixes Jindrake's breath spray with pheromones (it first caused Jindrake to attract a squirrel and later a chimpanzee named Tad from the animal shelter ) and steals Dobbs' personal schedule. Max even starts a food fight when the Superintendent visits. Later, he ends up using a crane to spill the melted ice cream on Dobbs and the Ice Cream Man during their exchange/scuffle.
Max is invited to Buddies for one milkshake before Megan and Robe's going away party (but drinks about twenty instead). He achieves the popularity and revenge he wanted, but he upsets a lot of people in the process, including his best friend Megan (Zena Grey), who had secretly had a crush on him for a very long time. Even though everyone he took revenge on is furious with him, Max doesn't care because he's moving to Chicago. Then his parents tell him that they aren't moving after all because Max told his dad to take a stand to his boss. His dad did just that, and now he is opening his own business. Max is in trouble and now must fix what he has done.
He gets some helpful advice from the janitor: "Any one kid can make a mess, but it takes a man to clean it up." Taking this advice to heart, he sneaks into Jindrake's office and uses his camera to apologize to the whole school, especially Megan and Robe (Josh Peck), and calls out both Dobbs and McGinty, challenging them to a mano-a-mano showdown with them both: "It's me you want, so leave my friends alone!" Jindraike comes in and confronts Max for all his mischief, then, with the camera still running, spills the beans to the entire school about cancelling funding for all school activities so that he could erect the football stadium bearing Superintendent Knebworth's name in place of the neighborhood animal shelter. Little does he realize that, because his camera was on as he talked to Max, everyone in the school has gotten wind of his scheme.
Later Max meets Dobbs and McGinty on the playground for his climactic showdown, only to realize that revenge doesn't solve anything, and when everyone comes forth to gang up on Troy and Dobbs, Max explains this and that if a bully picks on you and you do the same thing to the bully, you would become like them. He then recommends to let them go, but not before throwing them into a trash bin. Max heads the bulldozer-driving Jindrake off at the animal shelter for another confrontation, but this time the animal residents render help to Max. In the end, Max chooses Megan as his new girlfriend, the animal shelter is saved, and the principal, whose devious plans had now been exposed, is subsequently fired. The film ends with Max doing his newspaper route... and being chased by the Ice Cream Man once again.