Try here:
http://www.montanaowners.com/
look for link to RV Related Links
http://www.montanaowners.com/RVRelatedLinks.html
down aways on the page find link for Winterizing The RV
http://www.montanaowners.com/RVRelatedLinks.html
And, the others will come along and provide more personal answers
Good luck
ON EDIT: Please note that the final page I have referenced here has a charge of $7.00. I was not aware of this when I posted here. I am sorry, and withdraw my personal reference to said page.
DO NOT WITHDRAW MY REFERENCE TO OUR HOME PAGE AND ALL THE OTHER GREAT LINKS.