In the beginning, to the north was Nilfeim, the land of ice. To the south was Muspelheim, the land of fire. Between the two was Ginnungagap, the void.
The void was filled with steam and sparks. The ice was melting, and out of the first drippings was formed Ymir, the first frost giant. It was from him that all others came to be. A man grew out of his left arm, a woman out of his right arm, and yet another son out of his leg. These were the first frost giants of the world.
Out of the dripping ice, in the cinder filled void, the second drippings brought forth Audhumla, the cosmic cow. Audhumla came to the void to feed off of the salty rime-stones. As she was feeding, Ymir fed himself off her milk. With her licking of the stones, the first of the race of man, Buri, was carved. Buri eventually begat Bor, and Bor begat his three sons: Odin, Vili, and Ve.
The sons, seeing that Ymir was a frost giant, decided that he had to go. Ymir had to die. They fought him hard and long. A sword to the arm, an axe to the chest, a spear in the side. At last, Ymir fell, dripping in blood.
Seeing that there were only the lands of fire and ice to live in, the sons decided that a new land needed to be formed. Ymir’s body was perfect for their purpose. They fashioned the land out of Ymir’s body: His hair became the trees. His bones became mountains. His teeth became rocks. His blood became the rivers and oceans. His eyebrows became the mountains to keep the frost giants out of the lands of man.
With Ymir’s skull created the sky was made. They had the dwarves hold it up at the four corners. To the east was Austri. In the west was Vestri. The north was held by Nordri. Finally Sudri held up the south. Odin, Villi, and Ve also directed the uncontrolled sparks from Muspelheim into the sky to become the stars.
So, with the sacrifice of Ymir, and the dismemberment of his body, the world was made by Odin, Villi, and Ve.