Using stairs in CAW

I have been reconsidering my harbour in Fenbury. The terrain is rather steep and when I initially tested it in game the sim walked straight off the cliff rather than down the slope which is currently the only way to get to the harbour. I have seen somewhere an image of a harbour with shallow steps leading down to it and reckon that might be a better way to go. I still have the routing to sort out so now would be an ideal time to try.

The trouble I'm having is finding some up to date instructions on how to build stairs into the terrain. I have seen pictures of it done in other custom worlds so I assume it is possible. I believe I have to create a lot and place the stairs within the lot. I understand there may be routing issues but I have those anyway. I believe it is also best to take a sidewalk as close as possible to the stairs to encourage the sim to use them.

Any help or tips would be gratefully received.