i did mine last week. Didnt break any, and now have the tool that i bought for $121 from napa that i cant return.
I had the motor running for 10 mins, turned it off, cracked each plug 1/8 turn...sprayed carb cleaner AND pb blaster in each plug (2 quick quirts each). Waited 15 mins and the plugs came out all intact.
Mind you...there was a ton of squeaking and cracking sounds...and i did them by hand, no power tools.
I wish I had come across this earlier like 2 weeks ago, I went in blind not knowing the history of these damn things. My neighbor (who claims he was engine rebuild at a ford dealer) said he would help me do this but he never gave me a heads up on what all's involved in this job. Having been a diesel mech in the Marines I thought after a while how hard can it be? I've taken mushroomed glow plugs out of HMMWV engines, can't be that hard!???
So I start I get lucky the entire right side comes off and goes back in no problem, "mr engine rebuild" finally comes out and does the 1st plug on left side way in the back, after that he takes off. I start wrenching on #3 and yup you guessed it the thing breaks, I change the last two no problem but have been going at this for over a week now.
I think I might have F'd the head up but screw it I ordered the kit to push the broken porcelain down and then pull out the broken piece. Had I known all the steps involved in doing this I would have gone and gotten everything and not be dealing with possibly having to replace the head. Waiting for the tool to show up and finish the job, not having a truck is killing me since wife and son both have broken legs and have appointments they need to get too.
I changed mine today ! did not brake a single one !!! I did exactly what was in the original post, except for adding some mouse milk, something we use on aircraft, it did wonders !!! thanks again for the advice !!!