I have removed part of the wall paper using warm water. It is, I think from the 1970's .
The only way is hard work! I had to take down wallpaper that had been up for years and some of it came off in very small pieces...as small as 1". You can score it and buy products to spray on that cuts the glue.
A wallpaper steamer is the quickest and easiest way for the job you are doing ,inexpensive to buy or to hire
Hi, Thank You for that tip.