Reduce it to near bow dimensions. Seal the back completely, and the belly in the thickness of the handle and fades. If it's still wet green just days off the stump I like to clamp it down on something, usually a caul with some backset. Anything will do as long as it's fairly even. Let it stand like that a week. Find a humidity gauge, home center, walmart, whatever. Keep it at around 50% relative humidity for another week. Then try to find 40% Rh and keep it there until it stops loosing mass weight. Usually a warm place in an otherwise cool environment, like the attic or a closet w/ a water heater in it. Use any scale that will measure the weight accurately to within 1/2 oz, perhaps one of those "weight watchers" scales or similar you could find in the kitchen section at most department stores. Need a max capacity of about 2#.
Six weeks is not an unreasonable estimate of the time required to go from stump to tiller tree. But care must be taken, particularly in the thick area of the handle. And it's not best case scenario as the stave might well continue to equalize over time, resulting in change of tiller in worst case scenario.
I ain't above working wet green wood, but get better results overall if I start with stuff at least a year off the stump.
Get yourself a number of caches going, cutting as soon as is practical, then you'll be ready in coming years.