I put trains in the game by the following:
(note before you start this it would be wise to create a backup of all the effected files until you know what you are doing)When you go to your download it is usually downloaded as a zipped folder. You first have to open the zipped folder and you should see a few files. Most times it will be a folder file with an abbreviation of your trains name. Other times you will find the above file along with a picture, a readme document, a file ID document or any comdination of these files along with some possible extras. You will want to focus on the folder file with the abbreviation of the trains name. copy and paste this file into the trainset folder, which is in the trains folder which is in the train simulator folder. This method works 80% of the time. Of course there are exceptions that reqiure completely different processes.
Hope this helps and doesn't confuse you more. If your computer crashes in the process, I take no responsibility.[/b]