Pitchfork or 5 prong will loosen it up. Or if they are to overgrown use a spade to dig them up and a hard rake when you are done to level out the dirt. Get as much of the roots as you can and tell her to lay a pre emergent to prevent them coming back. If you have not done this kind of work before you will not know how long it will take you so get a piece of paper physically clock in when you get there and clock out when job is done and charge her xx dollars per hour make sure its worth your while it is hard work. Also if you are taking debris away be sure to add the dump fee into the job price