I found rubbing on warm or hot water with a sponge and it comes right off. It's a slow process but it works.
I use a 50/50 mix of vinegar and hot water. Wet down the wallpaper. Scrape off with a putty knife. Use the same mixture to clean off any glue residue.
I will try both of the methods which were provided to me. Thank you both.
Great way to spend a Saturday, eh ?