They should have included the tram as a prefab... It shouldnt really be that hard if you know all the hammer tools. Make the side you want, clip out the windows. Clip a bit of the lower area without removing anything and VM the very bottom to get that little slant.once you finish all that, go back and apply the inside textures. For the door, you need to have a second train with the same origin. Tell them to follow the same path or track, when the tram stops have the door continue on a differnt path for it to open.
The barney is just a bit of scripting, something I've never done.
The door is 2 doors, 1 that goes up, one that goes down. I think the bars at the top and bottom are doors too. I guess the rotating circles are just func_rotating, but I cant seem to get that thing to stop once I start it. If you can great, I would just use a rotating door.