At this point, the trick is to get the clay to dry out, but not dry it too much.
Optimally, if you are going to do this a lot, you will want to make a big plaster bat, a large plaster surface that you could work the clay on. (Plaster absorbs water, pulling it right out of the clay.) However, if this is a one shot deal, you can use the same idea without the plaster bat. Find some towels that you don't care about saving; you can hose out the clay and wash them clean again afterwards, but the clay may irreversibly stain the material, especially if you are working with red clay.
Working outside, dump the clay onto the plaster bat or onto the spread out towels. Spread the clay thinly, about two to three inches thick. Let the clay sit for a time, checking on it periodically. In hot, dry weather, this step may only take an hour or so.
When the clay can be formed into a ball without sticking to your fingers, begin gently scraping it off the plaster or rolling it up off the cloth. Putty knives work well for this, especially the really cheap plastic kind. If you used plaster, be certain no plaster particles get into the clay.
The clay will probably still be very soft. Work it in your hands or on a piece of canvas to dry it out further. If you are planning to hand build, just work the clay a bit to compress it and remove any trapped air. If you are planning on throwing the clay on a potter's wheel, then you'll need to wedge it, to ensure that all air is removed and that the clay is homogeneous.