To get rid of moss, you'll need to change the environment that encourages moss. Moss will grow in compacted soil, low fertility, low pH (acidic soil), low light (though it will also grow in sunlight), and moist environments (though some species also tolerate dry sites.)
Here is our webpage on moss and how to control it in lawn situations: http://extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/HG100_Moss...
The above publication discusses mechanical and chemical control. Both of these methods will provide temporary control only. For a more permanent solution, you need to correct the conditions that favor moss growth.