Speaking from a position of absolutely NO experience with this problem, I'd ask for field service, especially if axle replacement is fairly "simple" for their service crew. I assume you have no power to the good axle, due to the differential design. Is it O.K. to move the front axle without doing further damage?
We do, however have experience with moving heavy stuff. I liked the blocking under the axle, feared overloading a standard "dolly", or driving it into the ground, and feared toppling the jack even more (but the bucket would keep it up).
If you can get the trailer to the front of the tractor, I'd set a jack stand under the axle, lift the bucket, and back the trailer under so the bucket is on the bed. Then elevate the tractor, and slide/drive/winch it on. Might have to fiddle with the ramps - they should slide apart or be removeable and let you get closer, then go back under for the rear wheels. A little water on the flat bed works wonders, even if it's metal.
Otherwise, we make HD dollies out of doubled 3/4" plywood with store bought wheels (Home Depot, etc.). It's easy to divide a lot of weight by four smaller wheels. You must be looking at supporting less than a ton on the front, right (1/2 tractor weight)? Need a handy dolly to set implements on around the place, or to convert into a rolling wood rack for the stove? You can take it apart, make it another size, or whatever, too, because everything is screwed together.
Get four 300-500# dolly wheels (the ones that rotate in any direction) and a sheet of 3/4" exterior grade plywood (or make up a "raft" out of 2x4's), double up the plywood to your preferred dimensions (we use 16" x needed length a lot, because we get six pieces out of a 96" sheet). Secure the pieces together with bugle heads, a.k.a. sheetrock screws - 8" to 12" spacing an inch back from the edges will do. Screw the dollies to the bottom with 1" or so heavy screws (drill first and size all screws not to protrude through top). In this case, the plywood is just holding the wheels in one place - you don't even need it, but you probably don't want to bolt the wheels to your bucket, do you /w3tcompact/icons/grin.gif?
Put that under the bucket, retained with a couple of those 1500# nylon ratchet straps. Keep the bucket level so you don't load the front or back set of wheels more. Lay a piece of plywood on the ground for a "road" to your trailer, and keep the other front wheel down a bit for a slight amount of steering. The tricky part is getting on the trailer, which a sheet of plywood makes easier. Boards work if you can keep on them. You can keep moving the plywood or boards by setting the good wheel back down and sliding your road forward or backward as needed, and angle the bucket to roll smoothly up the ramps.
We love playing with our dollies /w3tcompact/icons/love.gif. If you put another one under the back, you could push that <font color=blue>Big Blue Beast</font color=blue> to the dealer! This is how we lived without a tractor all this time /w3tcompact/icons/sad.gif.
