You don't need to take the axle nut off. Lift the rear of the quad with whatever means you have. Remove the wheel, upper and lower outer control arm bolt. Take something and tie the upper control arm up out of your way while working.
Hold the axle shaft with a pair of vice grips (I always wrap the shaft with a piece of leather so I don't score the shaft). While holding inward pressure on the shaft hit the outer joint outward a with either a brass hammer or dead blow. It should pop off the hub will come off with it as an assembly. All that is holding it is a snap ring. Clean everything, install the boot add grease and reassemble. The cv should go back on with a moderate hit to the end of the axle, once again I use a brass hammer.
I tore a boot on my first ride and had to do this in camp. Luckly I brought along some boots that fit my other quad not the right ones but got them to work so I could ride the rest of the weekend.