How difficult is it to change out the wallpaper in a TT?

I'm just shooting from the hip here, and I'm certainly not an expert in the matter, but I would imagine it would be OK to use a good grade wall primer - (Zinzer's is a professional grade product available at Home Depot) - which can be used on just about any type of surface, and will provide a good solid surface to paint or wallpaper over. I'm pretty sure it holds up in extreme weather, because they even recommend using it on your rain spouts outside. The only reason I know about this is that a friend of mine, a professional paper hanger himself introduced me to it, and I used it in my house to paper over an existing wallpaper. It's certainly worth researching.