There is an incredibly easy method to obtaining both this and "The Great Escape" achievements.
Before entering attempting this, ensure that you have the "Magical Tiara" item, which grants you unlimited magic, as well as either the "Super Mega Puff" or "Flamethrower" spells. Ensure that you have one of the aforementioned spells equipped, then begin the sliding sequence. As soon as you can jump, perform as high of a jump as possible and hold down the magic button. Flamethrower and Super Mega Puff allow you to float in place, and with the Magical Tiara you will never run out of magic, allowing you to float in place indefinitely, floating you over the entirety of the course. When you reach the cutscene, the achievement will pop.