You do not need to have someone do it for you, just get the valve at the bottom of the tire, and remove the valve core, and the ballast will begin coming out. When it slows, just add some air and it will start again until you are down to valve level. If you want some control, jack up the tractor and start with the valve at the top, and rotate the tire down as the fluid level drops. Your only problem will be what is left below valve level when you are done. You can either break the tire down or find something small what can be inserted in the valve and attach this to a hose and pump or maybe even siphon. You should catch the outflow and properly dispose of it (save it for the first good ice storm). If you don't want to do it yourself, most tire shops that put the stuff in also remove it.