If you pop the seal out first and spin the nut back on the end of the shaft you can then lever VERY GENTLY on the under side of the nut with a pry bar (place a piece of wood or other soft item between pry bar and barrel) or as someone once suggested on this forum use the end of a claw hammer (the bit that you use to pull out nails). If the power valves arent coked up to badly they should pull out easily but be gentle with it to much force could damage the p.v.'s or worse the barrel.If they are coked in badly try soaking them with contact cleaner for few days or buy the proper tool.