Teacher's Pest

The following plot was taken from TV.com. Feel free to expand it!
Walter (James Callahan) wants Jamie (Nicole Eggert), Sarah (Josie Davis) and Adam (Alexander Polinsky) to do stuff they did when they were little, tired and not wanting to hurt their grandfather's feelings they tell Charles (Scott Baio) to talk to Walter and tells him to enroll in a College class he refuses by saying "You Can't Teach an Old Dog New Tricks" and refuses, but he changes his mind and decides to participate and he learns that Charles will be his substitute teacher and when Walter keeps being the teachers pet and raises his hand when Charles gets the date wrong in the War, he later popular and having no time for his grandchildren, they kids demand that they want their grandfather back. Since Walter can't take Adam to the father/son banquet Charles takes him and breaks a date to do it, Charles's date offers to take Walter to a sorority party and Buddy (Willie Aames) decides to double date with him, Charles then tells them that they have to write a 10 page essay, after reading Walter's paper he's determined to give give him a "F" for not using the text book information, after looking at the text book himself Charles realizes that the book is wrong and invites Walter as a guest speaker to talk to the class what he saw through his eyes during the War.