What's the best way to remove 20 year old wall paper?

Score and steam!

https://www.lowes.com/projects/paint-stain-and-wallpaper/remove-old-wallpaper/project

I found this site useful:

https://www.sfgate.com/homeandgarden/article/There-s-an-easy-way-to-remove-old-wallpaper-3276383.php

I guess a hand held steamer, would work. First spray with hot water the wall and then steamer. Rent one, you need then one person to help.

It seems like everyone I've talked to has their own best methods! A couple of people mentioned using wallpaper removal kits with sheets - like this: https://www.amazon.com/Simple-Strip-HydroSheets-Wallpaper-Removal/dp/B000UVDTBG/ref=pd_bxgy_60_3?_encoding=UTF8&pd_rd_i=B000UVDTBG&pd_rd_r=2HAZXFWK4WGP9270H8W3&pd_rd_w=pPiBQ&pd_rd_wg=qNz7l&psc=1&refRID=2HAZXFWK4WGP9270H8W3&dpID=31wP27FX5iL&preST=_QL70_&dpSrc=detail

Downey fabric softener and hot water in a spray bottle about half and half ratio.spray on wall let sit for about 5 minutes. Scrap off really easy

If you don't want the hassle (and expense) of renting a steamer, I've found that filling a spray bottle with warm water and soaking the wallpaper makes it fairly easy to scrape off. Spray about a 4' x 4' section and wait about 5 minutes or so before scraping. The wallpaper usually peels off easily. Make sure you don't gouge the wall - if there's too much water sprayed on the wallpaper, it will soak through to the wallboard and you can gouge that with your scraper as you're removing the wallpaper. I've also found that I don't need to score the wallpaper before spraying unless it has a vinyl or shiny surface, like kitchen or bathroom wallpaper. If it isn't scored, the water can't penetrate to the paper underneath making it next to impossible to peel off. Good luck!

Letting the warm water soak in is really important to make it easier to peel. I found those sprays don't work any better than warm water. Patience and elbow grease are the best removers.Use texture rollers or an old sponge with joint compound or texture "mud" to create a texture to hide any gouges. A scraper or trowel helps make a knocked down texture. Good luck on a big job.

spray it down with fabric softener and water