I'm trying to remember here since it's been forever since I've played Sims 2, but I think you have to build the lot, save it to the library, then export lot to file. Since the Exchange is no longer alive, you have to upload it to a third party site like box.net then provide the links on your LJ. You can link the download here but you have to host the file somewhere else. It should appear in your EA Games or Electronic Arts folder on your computer under Saved Lots.

Sure. I'll try to remember as much as I can.