Do you know how to turn a single player world into a multiplayer server in Minecraft?

My friend I are are both working together on a single player world. Unfortunately, I have to come over to his house or use his laptop to work on it. The only way we can work together usingon different laptops is through LAN, but we don't want to give each other our Wi-Fi passwords to do this.

When you set up your multiplayer server and ran it once,
1) Go to your start menu and search %appdata%
2) Click "Roaming"
3) Click ".minecraft"
4) Find the "saves" file
5) Find the world with the work
6) Copy the world file and paste it into your multiplayer server files. Rename it to be "world"
7) Delete the OLD multiplayer "world" file.
8) Run the server and your good.