Use the tip of a pin or needle to gently “score” the edge of the adhesive liner to make it easier to remove. If you have a roll that is “sticking,” try running your finger along the edges of the paper to remove any excess adhesive that may be preventing you from peeling the liner away.
We also learned a helpful tip from our friends at Oliso Irons; they “crack and peel” the backing to more easily remove it from the adhesive. Crack one edge of the paper, or create just a tiny tear, and that should aid removal of the liner.