Here is a good video on replacing the stove
You will need to remove the faucet and sink as well (our sink had screws extending up from the bottom- very hard to get to). There are probably L-brackets or something similar that hold your countertop to the base- you'll just have to look and see after you get the sink and stove out.
Its not complicated- just tedious.
Unless you really like the wallpaper, this would be a good time to put up a beautiful backsplash in glass tile or plastic "tin" tiles like these
to complement your new countertop.
It is a simple way to really update the look of your coach- check your nearest big-box hardware store for great ideas.