How far is the nearest water? The safest (and easiest) way to get her off the trailer is to launch and float her off, then hire a professional boat mover with a hydraulic trailer (as shown here
http://www.brownellboattrailers.com/trailers/onroad.htm) to bring her back home and set her on keel blocks and jackstands. The trailers used by profesional boat movers have hydraulic cylinders to raise and lower the whole rig allowing the boat to be set on keel blocks. After setting the boat on keel blocks, and putting a pair of jackstands at the transom for side to side stability, the trailer's removable cross members are taken out, and the trailer can be pulled out from under the boat. The final step is to add another set of forward jackstands.
I strongly advise against trying to raise her up with jacks and blocks, then pulling the trailer fwd, a few feet at a time, juggling blocks and stands around the trailer cross members.
This is DANGEROUS business. I wouldn't be climbing around between the trailer and the boat juggling jackstands and blocks. I've done it before with much smaller/lighter boats, and it's a very scary experience when something moves unexpectedly.
I store my boat at home, which is about 2 miles from a launch ramp, and it costs me $9 per foot for professional launching / hauling which is $234 for my F-26. If you have to travel farther, there will be a milage charge. I'll bet you are not going to find a safe way to lift her off the trailer for less than that.
Good Luck,
Chuck