Complex sentence: Instead of rejoicing in the discipline-less school, Bart feels bad about causing Skinner's firing, so in an effort to get Skinner his job back, Bart attempts to expose Flanders's poor leadership to Chalmers.
Split into simpler sentences: Instead of rejoicing in the discipline-less school, Bart feels guilty about causing Skinner's firing. In an effort to get Skinner his job back, Bart attempts to expose Flanders's poor leadership to Chalmers.