How do you remove Pampas Grass

So I have a new maintenance customer, and I talked her into doing a bit of a cleanup. She has 4 plant I want to take out, 3 being VERY large Pampas Grass plants (bases are 5 ft in diameter) and a Cotton Easter taking up about 70 sq ft of area. My problem with the Pampas grass is only one is accessible for my truck or any other type of machinery. The other 2 are located in the side of the yard in her tiered landscape. Do I just plain have to dig them out? Or can I cut them short and spray them with some pesticide? Also, there is a large cotton easter that is out front by the pampas grass, it is right next to the water line and its trunk is rested up against the mow strip. So I figure I probably shouldn't just rip it out with a chain... Can I safely chop it down and remove the stump without worrying about the roots that shoot might be under the lawn and etc...?