Here is a link to the TSB on changing sparkplugs in the 04-08 Modular Ford Engines.
I have a 99 F250SD with the 6.8. different plug design but I have only three threads in the head for the plugs so I have to be carful with plug changes too.
It was recomended to me to just break them loose then soak them with PB blaster or something simular and let that soak in to break up the carbon.
66 California Town Hardtop Thunderbird 428
81 Ranger 4x4 2.3
99 F250 SD 4x4 6.8 V10
10 Polaris Sportsman 800 X2
4" Proline Dredge 6.5 Honda