Ive been making little keepsake boxes outta old boards and have to remove the grip on each one before sanding, cutting then glue up. So Ive done a bunch of them.
Heat-gun or hair-dryer softens up the glue. I clamp the board to the work table, heat up the edge of the nose and then take a razor and get it started. Pull enough grip up to be able to stick it to a thick wooden dowel, about 1" or thicker. Then with the heat-gun, warm up the grip while rolling the dowel down the board making sure the grip is sticking to and rolling on the dowel. Most grips will peel off pretty easily. If it starts peeling away in pieces, stop and re-stick it to the dowel, then start rolling again. Once you get this technique down, it'll take less than 5 mins.
If done properly, the grip will roll right off the dowel in one piece and you'll be ready for the next one. The clamp is the saving grace on this job. If frees up both hands, so get a good size clamp. Heat-gun and a 12" grip clamp is prob $20 each or you can get a hairdryer from thriftstore for cheaper. Dowel will run you $5.