I was told by Monaco that for the longer strips of Eternabord they loosen one end and try and roll the end around a bottle. From here they attempt to remove it in one go by wrapping it around the bottle all the way.
Otherwise there is only one solution ( my favorite): Brute force and ignorance
As described earlier, I would use a glazing knife while being very careful not to damage the surface on which it sticks to. Remove whatever you can get of with a solvent.
A while back one of the more experienced IRV2 members recommended to me 3M General purpose adhesive cleaner
. You can buy this in some of the bigger autoparts shops. I have used this many times and I am pleased with the product. Be sure to protect your fingers when using it - it is strong stuff.
Time to roll up the sleeves and get started