The tut is very easy.
just follow it veeery carefully.
It worked for me. I tried it and now I know how to make your elevator. Just use the func_train thing.
Make your elevator, then tie it to the func_train entity.
Make point based entities, the path_corner ones were you want your train to go.it doesn't matter where you put the elevator, but the path_corners matter.
name the elevator something.
make the elevator's first stop target to the name of the first path_corner.
make the first path_corner's next stop the other one, and vise versa.(Not spelled right, I know.)
make a brush based func_button.
Make the button target the name of the elevator.
I'm not shure if it works, but I'll look at what I wrote then try it. I might have typed it wrong since I did this in like a minute.
Hope I helped.