Hello, PALL MALL,
Do you still need this dish?
Probably there is another way to bring it down - safely, and without renting fork lift.
Two pieces of 6' uni-strut, some more hardware (1/2 " U-bolts, steel nipple + ... ), 16' extension ladder, and 3/8 or thicker climber's rope - would do the job, no helpers needed.
Seems the dish is made of metal. Fiberglass dish usually has reinforcing ribs.
Even if slightly warped - it could be un-warped with braces.
Cheers, polgyver