Ive used one of these for last 4 years. Does a grand job
http://m.molevalleyfarmers.com/h5/r/molevalleyfarmers/mvf/store/products/express-gas-dehorner
http://m.molevalleyfarmers.com/h5/r/molevalleyfarmers/mvf/store/products/express-gas-dehorner