Hi. I recently picked up a Williams by Bachman scale Hudson  Great Northern 4-6-4 locomotive and tender and I have a few questions. The unit came with an additional snow plow with a coupler. I'd like to find out how I can replace the one on the engine with this one. The instructions aren't good at all. Also is it possible to put real train sound in this unit? It comes with the true blast whistle but I would like to put some other unit that would give chugging as well. Any help or advise would be much appreciated. Thank you and have a Merry Christmas.