Gather all your materials together, have a warm bucket of water and a sponge. Put your gloves on and set up the ladder in a corner where you will start to remove the wallpaper border.
Stripping off old wallpaper is easier to do then to try to paper over it,otherwise any peeling or blistering will show through the new paper.
Start in a corner, take your bucket of water and liquid soap and sponge. Dip the sponge into the warm water. Most wall paper may be removed by soaking with the warm water.
Apply the soapy sponge to the wallpaper, the liquid detergent will loosen the old paste and speed up to the soaking process.
Take your scraper and scrape the area as evenly as possible so you do not gouge new holes in the wall. Once the paper is loosened then it can be carefully peeled off by liftin the bottom edge of paper with your fingernail or stripping knife.
Peel each length straight up and off the wall. Vinyl wall coverings have a thin layer of backing paper that will remain on the wall as you pull the top layer off. If it is not torn then it can remain on as a liner for the new wallpaper. If the thin layer is torn it has to come off the wall. Continue to use the soapy sponge to loosen the glue, take the scraper and scrape upwards to remove the remnants of the wall paper border.
Washable and over painted papers are made to withstand water, so soaking the surface does not always work. If the soapy water does not loosen the paper. Score the surface with a steel brush or serrated scraper, then use the soapy water to soak the spot, when the paper becomes loose use the scraper to remove the remaining paper.
If all else fails, you may rent a steam stripper from your local home department store. The steam passes through a plate held close to the wall. It will loosen the paper enough for you to use the scraper to remove the paper.