Well, u can use doodads that look like a ramp, or just stack somthing liek the elivator as a stair, I'll post some screenshots tomorrow.
And they wont need any extra settings, when it's walkable it's walkable.. xD
Just try it out for yourself in the WE and you'll see.
Just don't forget to place pathing blockers at the sides you don't want the unit to leave. (So basicly they are walls the player can't see.)