Corona Steve, the Mennonites mainly clear by slashing and burning. If you have any trees that you wish to save - this would not be the route to go. Casey Moore of Island Consructions or Alvaro Guerrero of the Essene Way may be able to help you out. They have heavy machinery and will bulldoze most of the area, but they will save whatever trees or landmarks you request.
The other method is hand clearing, it takes longer and the crew needs supervision to save your trees.
Whichever method you choose, it is not inexpensive. Unless you are planning to either build or landscape you may want to reconsider clearing you land at this moment. Within 18 months, if you do nothing to the land, it will be overgrown again.