Well you may be able to rent a dump truck. Some places have small single axel dump trucks for rent. You may need a CDL if you are planning to travel on roads.
Another option is to use your tractor to haul the dump trailer.
I have moved a huge amount of lime and gravel with my tractor and dump trailer / or a rented lime buggy.
You can use the tractor to load the trailer and then put a 2" or 2 5/16" ball on the tow bar and pull the trailer.
But I think your problem is that your tractor is marginal for the task. I load the lime buggy without a rear ballast beacuse it takes forever to hook up the three point ballast, load trailer, unhook three point ballast, hook up trailer, repeat....
They only way I get away with this is my tractor weighs the better part of 10K lbs and I take small bits with the loader.
What ever you do, I would not drop the ROPS. Just to much potential to get hurt in order save a few bucks.
Another though:
Rent a bobcat and a dump trailer. You can use your tractor to pull the dump trailer and your buddy can load with the bobcat. /forums/images/graemlins/smile.gif
Around here you can get a bobcat for a weekend for about $125 plus delivery cost.
Just keep the loads small. Your tractor is no match for a full dump trailer of gravel.
Fred