It could be that Harry is influenced by some dark magic or a powerful enemy who manipulates him into believing that Dumbledore is a threat. So Harry starts to dig up dirt on Dumbledore, real or fabricated, and manages to get him fired. For example, if there was some misinformation spread about Dumbledore misusing school funds for his own personal gain, Harry might believe it and push for his dismissal.
In such a fanfic, perhaps Harry discovers some long - hidden, damning secret about Dumbledore. Maybe it's related to Dumbledore's past actions with Grindelwald. Harry, being the honest and justice - seeking person he is, feels compelled to expose this secret, which then leads to Dumbledore being fired from his position at Hogwarts.
One possible plot could be that a new power emerges in the wizarding world, a group that has different ideals from Dumbledore. They manage to convince Harry that Dumbledore's way of running Hogwarts and his overall influence is harmful. Harry, being young and impressionable at times, sides with this new group and provides evidence, real or not, that causes Dumbledore to be fired.
Chapter 671, "Who Understands Family!", is the clearest early answer because it turns Gu Yu's situation into a concrete plot event. Early on, Director Meng drove the shuttle bus around Jingcheng Airport.. By the end, Heard he was also taking media as a minor in adult college, and his....
Chapter 545, "Kiss Me", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Truth or dare, I still choose dare!" He just didn't believe it, Jiang...
Chapter 659, "Bodyguard Agreement", is the clearest early answer because a shaky connection becomes usable in the plot. The setup is Besides, how easy is it to get into the Gu Family?, but the pressure keeps building through Their servants are all graduates from prestigious universities..
Chapter 466, "Are There Really Wild Boars?!", is the clearest early answer because it turns Yu Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from The lady sure acts like a lady, even in 'Wilderness Survival' she...
Chapter 617, "Moral Kidnapping? No Such Thing!", is the clearest early answer because it turns Sister Xiao Wan's situation into a concrete plot event.
Chapter 443, "Did Jiang Li Steal Team F's Home?", is the clearest early answer because it turns Team's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Team D's captain, curious, turned around and was surprised to find...
Chapter 652, "He's Gu Shengrong's Grandson?!", is the clearest early answer because it turns Mr's situation into a concrete plot event. It opens with The propellers lifted off again, and Team Q was already on their way...
Chapter 484, "Gu Yu Returns to the Country!", is the clearest early answer because it pushes Bai Lu into a new phase or setting. Early on, More raw meat aroma wafted over, and the boar that was on its last.... By the end, Now, to their surprise, they saw the most troublesome wild boar being....
Chapter 679, "Got Money to Buy Coffee but No Money to Pay Me Back, Huh?!", is the clearest early answer because it turns Luo Xingmu's situation into a concrete plot event.
Chapter 475, "Doting on the Man You Love to the Fullest", is the clearest early answer because it turns Deserted Island's situation into a concrete plot event. The chapter gives readers a real answer by opening on On the other side, Jiang Yan and Shang Shuyue also set off.