I'm not a professional dirt guy, but, I have tinkered with it. Perhaps, one of the pros can chime in. I was curious as to why you felt it was nesecary to deconstruct the pond. Now, I understand your dilema. It sounds like you've made a valiant effort to save your pond, and therefore, you certainly deserve a response to your inquiry.
Providing that you can completely drain the pond and keep it dry enough to operate machinery in it, I see no problem. Sure, there may be a funky odor for a little while, but it should soon dissipate, as the muck dries.
From your description, it sounds like the pond is built on a slope. This would be beneficial, as it would allow for continuous drainage of the area. Your dirt contractor may want to first dig a drainage trench through the dam, and come back a few weeks later, after the soil has dried enough so that it can be worked.
Just a thought; I don't know if it would be applicable for your situation, but, you might consider informing your neighbor of your intentions, and asking them if they would care to purchase the pond from you. Good luck!
