Zinsser 02966 Zinsser, PaperTiger 1-Head Wallpaper Removal Scoring Tool

I've had good luck using a "Paper Tiger" https://www.walmart.com/ip/Zinsser-02966-Zinsser-PaperTiger-1-Head-Wallpaper-Removal-Scoring-Tool/20144814876 It makes a ton of tiny pin pricks in the paper. Then user a mister or wet sponge to soak the wallpaper. Go have a coffee and let the water soak through the holes. It increases the likelihood of the paper backing coming off with the vinyl. Still a slow and tedious job, but feasible. Good luck!