In certain cases it can be difficult to remove and that would mostly be in much older homes. However there are a few solutions to getting it off the walls. If you have an older home, like many of the houses we have in New England, with multiple layers of paper on the walls the best way to remove it is by steaming. You can purchase or rent a steamer from a home improvement store. Once you let the steamer sit on the paper for a few seconds you will see it lift and the paste loosen up. A putty knife will easily get the trick done. If the paper was put up in a newer home, it most likely was applied correctly and will be much easier to remove. This is why sizing the wall is so important, it makes the removal easy. You can of course use the steaming method or you can use a wallpaper remover spray. First you score the walls with a scoring tool and then spray on the solution. After letting the solution soak in, use your putty knife and start scraping. The last step is to sponge off any remaining residue from the walls and your done!