I know there are literally dozens of posts on this topic but I wanted to post my experience for anyone who might be trying this.
I have been dreading this day since I joined this forum and started reading the posts about breaking spark plugs. I am the type that Murphey loves and to compound it I am the least patient man you will ever meet. I have the whole weekend so I figured WTH I'm gonna get the plugs and go for it. I did not have the tool, cause I couldn't wait for it, so I was winging it. I will say I didn't break one plug all of them came out fine.
I ran 2 cans of Sea foam through the car with 93 octane (2 tanks of gas) in preparation for this.
I started the car and let it warm up then I pulled the COP's and broke all of the plugs loose and turned about 1/8 of a turn. Then I sprayed each hole full (above the hex of the plug) of Sea foam deep creep and walked away for 1 hr and 15 minutes.
When I came back I set my torque wrench to 30 ft/lbs. and went to turning. The plugs creaked a little but came out with little effort. When I pulled the plugs out they were wet all the way down to the electrode and black. The electrode was all but gone so I know they have been in there since day one.
Once I had all of the plugs out I cranked the motor a few times because there seemed like alot of fluid and I didn't want to take a chance on hydro locking the motor. I put anti seize on the threads and put the new plugs in. I got in the car and cranked it up and moved it back to the driveway. I didn't get a chance to drive it cause a bad thunderstorm came up literally as I was coming in the house.
One thing I will say is in researching this everyone said to use a 15mm socket but I found that a 9/16 fit better.
That's my experience and now that it's done I hope to have another enjoyable 100k miles hopefully by then I'll be ready to forge the bottom end and the engine builder can remove the plugs
As soon as this storm is over I hope to drive it and hopefully there will be a "little" difference like I said the electrodes were almost non existent.
Autolite HT1 plugs
2 cans of Sea foam in 2 tanks of gas (don't really know if it helped or not)
Sea foam Deep Creep
9/16 deep socket
7 mm socket for the COP's