It is hard but manageable, I get my weight directly over the winch (lowering the spray hood) and do it with a rest in the middle. Planning to replace the top block with a Barton size 4/5 triple ball race block, (the rope got caught between the pulley and the block sides, damaging the old block). Hoping that will make it easier. It might be worth checking the blocks and the run of the ropes, in case something similar has happened to you.
Peter Scrivens has a system with an electric drill to raise the keel, but don't know how effective it is.
I have not found it necessary to continuously grease the blocks or sliders, however my boat is kept out of water so that might make a difference. I also replace the lifting eyes in the keel top fairly regularly (2 to 3 years).