Spark Plug Stuck: Worn Hex Head.

[JonK]

On Sunday afternoon, I was doing routine Spark Plug replacement, 40k or so on my 05 4.4i N62 engine.

Cylinder 4, need confirmation, close to the driver's side with the least clearance my 5/8" won't grab anything. So I couldn't get it out. Rest of plugs I replaced it with ease. Put them back together now cylinder misfires....

I used the giant dentist mirror and flash light to see what's going on and I was able to to the plug is in there.

I ended up bringing it to a local German Mechanic Store, the older gentleman took a look at it with better flash light with his helper and diagnosed that "THE HEX HEAD HAS WORN OUT and NOTHING OTHER THAN PULLING ENGINE APART CHASE OUT FROM INSIDE WILL HELP.."

It was like a DEATH SENTENCE to my beloved(!?) X5. I have done some extensive web search but not much I could try. Smaller sockets, Kroil Pernetrating oil, perhaps break the head and use screw extracting tool?

On my previous E46 I was able to pull out plug when the top broke off but this time I have a worse clearance, and the top is still intact.

Any suggestions?