-Boot from the install disc holding C while booting.
-Select language and click continue.
-Select utilities>disk utility in the menu bar.
-Select the HD at the top of the list on the left.
-Click erase tab.
-Format Mac Os Extended (Journaled).
-Name Macintosh HD.
-Click erase.
-Quit disk utility, and continue with installation.
After the movie plays, and goes to the screen where you have to input information, click Apple key (command) and Q.
A box will pop up for you to select shutdown.
On the next restart, the setup assistant will come up with the welcome movie, followed by the registration screen for the new user to input their details.