I have a different brand, but I'm assuming it's a tapered shaft like mine. The way that safer than I the way I used would be to unbolt the gearbox, flip it over, and block it up so that it's resting on the platform instead of the gearbox. Put the nut on part of the way and take a hammer to it. I think some heat on the dishpan around the shaft would help quite a bit as well. Obviously there are a lot of safety considerations here that I've not mentioned.