Score the border edges with a utility knife
Mix warm water with wallpaper remover or vinegar
Apply the solution with a sponge or spray bottle
Let it soak for several minutes
Gently lift an edge with a putty knife
Peel the border off slowly
Reapply solution to stubborn areas
Scrape remaining adhesive with a putty knife
Clean the wall with warm soapy water
Let the wall dry completely
Patch any damaged spots if needed
Sand smooth before repainting or rewallpapering