Peel as much as possible from the walls.
If you can't get to the backing, you may need to score the paper with a tool. Paper Tiger is easy to find. Light pressure because you don't want to damage the wall behind the paper.
Mix 50/50 fabric softener & warm water in a spray bottle or garden sprayer. I've read that vinegar is as effective but I have never used it.
Allow the mixture to sit for 5 - 10 minutes so that it saturates the adhesive on the paper backing.
Scrape with a plastic scraper.
Once it is all removed, wash the walls with warm soapy water (blue Dawn is my go-to) and a microfiber cloth.
A wallpaper steamer has worked best for me.
I agree, a steamer is the way to go!
Here's a video that might help - https://www.youtube.com/watch?v=2Mj26IwwEiY
Here's a quick and easy way to remove wallpaper.