Nukeworker brought up a great point!!! Most people do not realize the importance of knowing what is on the other side of what you are about to cut let alone within about 150' Most of the time when I do these I will plug the front legs allowing the machines pulling the plugs to be on the back side. My latest water tower is on youtube. Search flint powerhouse and watertower demo. Hope all is going well.

Scrappy, if you have the room to drop it that's the easiest way. Make sure you r cut the center stand pipe out. Yuo can do this at ground level; just take out about five or six feet so there is no chance of it hanging. Once you determine the direction of fall, you will need to attach somoe rigging to the front legs and run it back through to your pulling equipment. Cut the front legs in a set cut and the back legs in a hinge cut (keep a watch as you are cutting in case of settling). The idea is to pull the front legs out from under it so that it hinges over on the back legs.
Once it is down, you can cut it up pretty easily. As Nuke said watch out for the inner coatings, they can be ashpaltic or waxy and are usually flammable.
PM me if you need any pointers!