The best method to remove wallpaper glue, particularly if it is old, is to steam it down. That might mean renting a portable steamer, but in a well-ventilated area, try combining the use of steam and commercial wallpaper adhesive removers.
You don't have to remove old wallpaper to hang new wallpaper, however, depending on the quality of the new wallpaper it might look better if you do remove the old paper first.
form_title= Bathroom Wallpaper form_header= Add wallpaper to you home. What color wallpaper do you need?*= _ [50] What are the dimensions of your bathroom*= _ [50] Do you need to remove old wallpaper?*= () Yes () No
form_title= Brick Wallpaper form_header= Add depth to your home with brick wallpaper. Where are you installing the wallpaper?*= _ [50] How much wallpaper do you need?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No
form_title= Butterfly Wallpaper form_header= Create a dream oasis with butterfly wallpaper. Where are you installing the wallpaper? *= _ [50] How much wallpaper do you need?*= _ [50] Do you need to remove old wallpaper*= () Yes () No
form_title= Beadboard Wallpaper form_header= Install new wallpaper in your home. What color wallpaper do you want to install?*= _ [50] Have you ever installed wallpaper?*= () Yes () No Do you need to remove old wallpaper?*= () Yes () No
form_title= Purple Wallpaper form_header= Install purple wallpaper in your home. What are the dimensions of the room?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No Do you need someone to install the wallpaper?*= () Yes () No
form_title= Designer Wallpaper form_header= Install designer wallpaper in your home. What designers are you most interested in?*= _ [50] What color wallpaper do you want?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No
form_title= Paintable Wallpaper form_header= Add your personal style to your home. What rooms will you be installing the wallpaper?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No What color would you like the wallpaper?*= _ [50]
form_title= Damask Wallpaper form_header= Install new wallpaper in your home. What color paper do you need?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No Do you want vinyl Damask wallpaper?*= () Yes () No
form_title= Mural Wallpaper form_header= Add character to your home with mural wallpaper. How much wallpaper do you need?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No What would you like featured on the mural?*= _ [50]
form_title= Wallpaper Steamer form_header= Remove wallpaper with help from a steamer. How many rooms have wallpaper that needs to be removed? How long has the wallpaper been installed?*= _[50] Have you tried other forms of removal?*= () Yes () No
form_title= Map Wallpaper from_header= Travel the world with map wallpaper. What are the dimensions of the room?*= _ [50] Do you need to remove old wallpaper?*= () Yes () No Do you want a detailed map?*= () Yes () No