BTW... Check out pclarksurf's posts.... I think in his last thread there are some good picture examples of how to set up lumber to build a cradle for the hull when removing the trailer.
You need to consider one of two strategies; your keel is half off... it will fall off when you try to remove the trailer unless you do one of two methods;
1. Unhook the lifting cable from the end, you already have the hangers unbolted. Lay some thick foam or other thick padding on the trailer frame and use lumber to brace the keel. With the transom supported by a cradle or boat stands you'll lift the bow with your cherry picker; as you come up with the bow the keel will clear the pocket and someone (very carefully) will have to monkey with bracing and gently guide the keel to allow it to lay over to its side on the padding you placed on the trailer frame. WARNING, this can be unsafe unless you plan very well.... That keel weighs over 500 pounds!
2. Don't unhook the winch cable and get bolts back into the hangers, they don't have be tightened down fully, just wrist tight. As long as your keel winch is functioning properly and keeps the cable securely in the up position and the hanger bolts are in, the keel will be fully supported and stay put under the boat as you remove the trailer. Then you can slide a lumber cradle (hopefully on wheels) under the boat, lower the keel into it, brace the front, remove the hanger bolts and allow the front to come down (slow, use a jack).
I know all this sounds like a TON of work, but right now that keel is dangerous until properly repaired. If you have a plan, gather your supplies, and have a few helpers with you, this job can be done in two or three weekends and you'll be sailing by August or sooner.