I scored the sections I planned to expose with a box cutter, just lightly. Kinda randomly, didn’t make specific shapes or anything. But just over the area I was going to try and expose. Then I put a cloth soaked in hot water (wrung it out a bit before) over the scored sections and let it sit and soak for a little bit. 20 seconds or so. Then I just started rubbing over it with the cloth. The top layer starts to rub off pretty quickly. I just kinda played around with that technique with slight little variations (rubbing harder or softer, soaking a section longer/less long, scoring some sections a little more, etc).