OK.......I'll take the possible bait.
First LMGTFY = Let Me Google That For You.....A nice way of suggesting to use Google search.
Next:
1. Drop the notification shade and access settings.
2. Tap or scroll down to Display settings depending on how you have your Settings menu configured.
3. Tap Wallpaper and theme
4. Tap wallpaper you would like to select. The psychedelic one I've seen in the promos is second on my list. There is also a wallpaper with a number on it if you would like to see additional wallpapers.