How do I remove pasted old wallpaper pasted to wood panelling??

To get a smooth, clean wall, mix hot water, some liquid dish soap, and a tablespoon of baking soda together in your bucket. This solution is going to help soften the glue enough that it will be easy to wipe or scrape away.

you could try a steamer that is used for wallpaper remover you can buy them or rent them

here is more info

https://www.familyhandyman.com/project/the-best-way-to-remove-wallpaper/

Use a tool called paper tiger to score small holes in the wall paper. Mix 50/50 warm water with either white vinegar or fabric softener. Saturate through the holes and use a steamer to loosen after it sits 5 minutes.

You can use a fabric softener mixed with water for this. And if you want to use vinegar, mix it with water in a 50/50 ratio.

Once you’re done preparing the remover, you can start applying it. Do in small sections to make the work easier.

You’ll have to spray the remover 10 minutes before you start taking off the wallpaper. It helps to soak up the wallpaper and make it easy to take off.

When taking the wallpaper off, use a putty knife to have clean wood paneling. Once you’re done with all that, spray the remover again and rub using a sponge

You can use a BBQ grill scrubber to remove the glue.

ref:https://homearise.com/remove-wallpaper-paneling/

Warm water alone may do the trick. Use a spray bottle. If that doesn't work, rent a steamer. Here's a link:

https://myblessedlife.net/2013/09/how-to-remove-wallpaper.html

Renting a steamer is your best bet, it will be a faster job than spraying with warm water.