well to rail on concrete you're gonna need to install a rail of some sort. if you just wanna grind it though all ya gotsta do is go at 'er and slide that shit. wax would prolly help but i've grounderded concrete without wax and it worked. bring some wax though for sure. oh and DO NOT use skis that you ever want to use at a resort because it fucks your bases.
"My penis isn't even that big I don't think." -Itsbackfliptime