Free floating first person camera

The premade first person camera prefab only offers 360 degrees of vision. How do i edit it so instead of the mouse going off screen to turn 180 degrees left, its as if the whole body turns 180 degrees and the mouse stays on the screen as in most first person shooters. Can i edit this in the free version of unity?

While I bow to the expertise of Eric5h5, :) I did want to add something, specifically to the question about editing the script files. Which you can easily do, in any version of Unity. If you look in the Projects tab, under Standard Assets->Camera Scripts, you'll see MouseLook. This is the script attached to the Camera in the FPSController, and you can edit it just like any script.

Note that you will be editing the copy of the script that was installed under your current Projects directory, so any new projects would not have your changes.

The main thing I changed in mine, is to set rotationY * -1, to invert the mouse. Otherwise it drives me nuts... :)

With the first person controller prefab, it doesn't actually matter where the mouse pointer is; it still reads relative mouse movement regardless. You can use Screen.showCursor to hide/unhide the mouse cursor if you like. There's also Screen.lockCursor, which will lock/unlock the mouse cursor to the center of the screen.