...I am located in Cyprus (Europe)...
Very cool. We'll look forward to hearing more about sailing there. There should be rigging companies not too far away, or sail to them maybe? (if she's safe)
Unfortunately Alone is what i had in mind just about as with everything else. I suppose if i take it slow and do it properly, there shouldn't be a problem
The primary issue is whether the boat has enough ballast to stay upright, with your weight on the mast. The further up you go, the more tenuous. Perhaps you have a place to cleat down both sides of the boat to make it safer. Some smaller boats are nimble enough to actually take a halyard, attach it to shore and pull the mast over. Obviously, if this is possible, you shouldn't be up on it. I just don't know, with your particular boat.
Rock climbing would certainly help with knots and agility. There are some things pretty unique to climbing a mast, like the ballast I mentioned, or preferring a line that goes through a sheave, not a block hanging off a crane, as examples. By the way, always tie a knot to your chair, do not use a shackle.
All the best with your project.