The book states to remove the inner wheel arch liner, which isn't the easiest thing to do.
However, if you are quite nimble and flexible, you can get them really easily from under the rear bumper.
To be honest, getting to them from underneath, is much easier than taking the liner out.
Place down an old rug or something soft to lay on.

 

That's a good tip, I am looking to do the same thing. Is it a straight shot up looking from underneath or do you need to wiggle around things?