How to buff the best way a car that was keyed?

[xxnonamexx]

I have not seen the car yet my cousins father in laws acura was keyed and he just wants it buffer the best it can. What can you recommend? I only can buff it by hand since I sold my buffers but I do have the 3" buffer to apply wax if I can use that in this case to buff out the scratch. Any tips? Thanks