Theres the front one right in front of the radiator.
The one on the left that you have to remove the air box to get to.
And the one on the right which is easy to get to.

So one more at the back, how do you get to it and is that it, just 4?

Just the four.
The back one you can get at from the top if you have a few flexible extention bars, otherwise its from the bottom and real slowly. Enjoy.:D

The one on the left can be undone by taking out the 4 plugs under the gaurd, behind the wheel.