It became all too clear, rather quickly, that Albus had overestimated his newest protege. His power was there, he had been right about that, but they did not share the same motives. All he lusted for was death and power, and he could not be reasoned with. He saw no irony at all in a genocide against Muggles given his own half-blood status. In the end, it was nothing more than a failed attempt, and he was quickly growing into a nuisance.
The plan to dispose of him was simple but lengthy. If done right, he would end up with another pawn to add to his set. As Gellert always said, raise them up in the way.
It was too easy to convince everyone that Sybil Trelawney had an honest-to-goodness prophecy, for once in her life. Everyone wanted to believe in their hearts that the hack was good for something, and of course she would believe it herself. Once someone believes it wholeheartedly, that's the moment a prophecy comes true. It was the beginning of the end for the Dark Lord Voldemort.
Stilll, Albus was content to bide his time, poking and prodding whenever necessary to achieve an outcome. So when Harry's name was drawn from the Goblet of Fire, of course he allowed him to participate in the Triwizard Tournament, despite the dangers. A wizard that couldn't overcome peril was useless.
When the Order had to be reconvened, of course Harry was allowed to be part of it. The horcruxes posed a unique opportunity to test the boy's mettle, and he wasn't disappointed. It became clear, though, that he himself posed an obstacle. He was too relied on. Albus realized that the only way to truly test the boy would be to remove himself from the equation.
Staging his death was surprisingly easy. He found a tramp on the street, a Muggle who would never be missed. A little Polyjuice Potion and an Imperius Curse. Marvolo Gaunt's ring provided the perfect opportunity, though it was terribly disappointing how easily people believed he would be foolish enough to put on a horcrux. Not even for the Resurrection Stone.
Before his death, Albus made sure to send Fawkes somewhere he wouldn't be discovered: Nurmengard. There could only be one phoenix seen around Hogwarts at a time.
He had to admit, it was pure selfishness that drove him to attend his own funeral. Perhaps Gellert's egotism had worn off on him after all. It was a beautiful service that gathered a throng of magical creatures, not just witches and wizards. A white tomb. How fitting for Albus Percival Wulfric Brian Dumbledore, champion of good—the wizard who had given rise to two Dark Lords in his time.
It was sad, in a way, to leave Hogwarts behind after all he'd put into it and the years he'd spent there, but sacrifices had to be made. Once again, he garnered his freedom by shedding the responsibilities that tethered him in place. It was a new opportunity to make their dreams come true in the name of the greater good.