I think JD has the most used method. But if you are concerned about the effect they may have on the environment whilst resting in a landfill, you could do the following:
A. Save them up with other metals, such as used mower blades, pieces of 37s and 38 and Fultons, and when you get enough saved put it out by the road with a sign saying "FREE." It will be usually be gone overnight. But, if that doesn't work resort to method "B" below:
B. Do all of the above (include picked up parts left along the roadside from Fleetlines. Whenever you find Wood pieces from Fleetlines with the CC kits. you save those up and try to find the owner. Fleetliners are generous with their money and will give you a hefty reward for their missing pieces. Will too!). Read on.
Again, pile the metal by the side of the road. Only this time using your post-hole diggers and set in place nearby a 4 x 4 oak post. Run to the store and get some quick-set concrete. Pour the concrete and then tamp down the extra excavated dirt real good using the handle end of the diggers. Then secure the pile of metal to the secure post with a heavy logging chain. Forget the sign. The stuff will be gone even sooner. Post, chain and all.
You're welcome,
Charlie