You might try renting a 4x4 backhoe. Saw someone bury a good size tractor with a 10' bat wing while mowing next to a pond one time. They used the rear bucket on the backhoe to kinda lift up a little bit and pull it out. A bulldozer would be good too.

Good luck.

1991 4wd Toyota 22re, 1.5" ball joint spacers, 1" body lift, 33 Baja Claws, Aussie locker, Budbuilt crossmember w/ 1" drivetrain lift