These are probably all bad ideas, but we're grasping at straws here to avoid having to pull the cylinder head and replace it

(it's not my car, so I don't know much about it, all I know is the engine has 6 inch tubes down to the spark plugs) .The spark plug hex nut and upper porcelain have broken off. I've used the kit from Autozone, and he Leslie kit(I forget the part numbers), but those didn't work. I can't find extractors long enough to get down to the plug (oh, of course it's in the back too).

I was thinking about pulling the valve cover and the tube around the plug to gain better access to it, then at that point.....

1) Now, here's my probably silly idea/question (There are no stupid questions, right? This might change that O:-) ) can I WELD something to the top of the remaining plug to twist it out? I know, I know, gas is explosive so you would think that was generally a bad idea, but what if the fuel lines are removed and it's cranked a couple times (that should remove an gas from that cylinder too, right?)
(BTW, I'm absolutely not a welder, but I did read about not connecting the ground too far because of miniature arcs across bearings and what not, destroying the engine... But, I have found people doing it on old engine heads removed from the engine.... SO, if it's a possible solution (without blowing things up O:-) ) what type welder would be best to use?)

2) get a diamond tipped drill bit and drill the porcelain out, and use a flute to get it out?

3) use a larger drill bit to drill the sparkplug out completely and just use a tap to clean the remaining sparkplug threads out of the hole? In that case, how much trouble would it be to clean the cylinder from all the shavings?

If you can't tell, I'm not a mechanic O:-)