How to Take Off Wallpaper from Plaster with a Wallpaper Steamer
Move the hotplate to an adjacent area as you scrape the softened wallpaper and let the pieces fall to the floor.
Hold the hotplate in one hand, and hold the razor scraper in the other hand. By the time you finish scraping the first area, the steamer should have softened the next area. If the paper is not yet softened, it is generally because the paper is not porous enough. You'll just have to wait a bit longer.
You floor should be covered with a canvas dropcloth or towels to catch the wet wallpaper.