Carefully remove and patch the sheetrock .

What kind of patching will need to be done? Like filling nail holes or something major? Is it c'mon to be both glued an nailed?

To remove the chair rail, Simply run a knife along the seam between the wall and the chair rail. Use a small pry bar to pop the chair rail off. If it was glued on, you'll have scraping to do. Most likely it was nailed on and you will leave small holes behind when you pop it off the wall. You may need to scrape residual paint and caulking off the wall. Once that is done, purchase a small container of joint compound and fill in the holes with a putty knife. Wait until the joint compound is dry per instructions on the container then sand it. The spots will be very small and you can paint right over them.. It's an easy fix and a great beginner project. Have fun!

Here is an example of a toned-down chair rail.

Yes I have seen that pic and thought about it- thanks. Also, I am attaching another pic so the feel of the room is elaborated on.