How can I make flyers up using pre-cut door hangers? ?

In Microsoft word. I have a pre cut door hanger that is professionally printed on one side with my company name, logo, address etc. On the other side I'd like to print special sale information for the different sales that we are having so we can pass them out to potential customers. I thought I could just change the paper size and load it into my printer but how do I do this and have everything align up the way its suppose to?