Removing Plastic Oar Sleeves

heat gun - on low - and piece of wood to put up against them, "persuaded" by rubber mallet/framing hammer/small sledge... heat gun on the sleeves only, not the shafts, you want the plastic to swell enough to move it with the block of wood and hammer. Vise helps, pad the shaft with foam or towel before clamping and watch clamping pressure - you are just putting the shaft in the vise to hold it while you loosen the sleeve.

Thanks B4otter! I'll give that a shot. This gives me an excuse to get a heat gun...