I described how we lifted Miss Fidget's keel in a forum exchange about nine years ago - but I see its attached image is no longer there, so I'm repreating the article, plus image, here.
We lifted Miss Fidget's keel using two pulley blocks, one attached to the jib halyard and one to the end of the wire strop at the bow that is normally used to attach the tack of the jib. We attached a long line in place of the normal keel hoist rope, and led it from the keel through the pulley block on the jib halyard, then through the one on the wire strop at the bow, and then back to the jib halyard winch. We then hoisted the jib halyard well above the deck, and cleated it off. The block at the end of the halyard needed to be high enough that the keel would lift clear of the slot in the deck before the lifting rope reached the pulley block on the halyard, but low enough that the pull of the lifting rope on the keel had a forward component, to help the keel slide on the forward-slanting slot. (On the diagram, the lifting rope looks almost vertical, but it should be more slanted to the right than it is - sorry!)
We then lifted the keel using the jib halyard winch. There were some alarming groaning noises, but we decided that we weren't actually applying any higher loads than the various fittings would experience while sailing, and kept going, and the keel gently popped up!
Gilliane
Delphine, Parker 275, no. 41