Siezed sparkplug

One of my sparkplus is siezed and seems to be rounded. This is the first time I have changed plugs since I bought the car used. Three plugs changed easy but one will not move. I can't see very well don the tube but the socket just turns.
Anybody have any tricks without removing the head?

Is the socket exactly the right size and is it 6 point or 12? When you look inside the socket do you see only six flat sides? Use a six point socket that is the correct size. It should grab even if the sparkplug is rounded off. If the threads are damaged after the sparkplug is removed, there are repair kits to solve the problem.

Is the socket exactly the right size and is it 6 point or 12? When you look inside the socket do you see only six flat sides? Use a six point socket that is the correct size. It should grab even if the sparkplug is rounded off. If the threads are damaged after the sparkplug is removed, there are repair kits to solve the problem.
I'm using a six point spark plug socket and it worked on the other plugs fine. It just slips and doesn't grab at all. I think other people may have tried before me to get it out and completely rounded it. It's so deep in the hole I'm not sure of what to try next. Really don't want to remove the head besides the plug has to come out before the valve cover can come off I think.

So you know you may have a serios problem. First, talk to a Snap-on tool rep to see if there is any type of special tool available. The valve cover will come off with the spark plug in the head. An air hammer with a chisel might loosen it. If not, breaking the porcelain off and using a MIG welder to weld the equivalent of a lug nut to the spark plug so you can use a socket to remove the plug. At least half of the repair shops will tell you the only way to solve the problem is to purchase a new cylinder head.

So you know you may have a serios problem. First, talk to a Snap-on tool rep to see if there is any type of special tool available. The valve cover will come off with the spark plug in the head. An air hammer with a chisel might loosen it. If not, breaking the porcelain off and using a MIG welder to weld the equivalent of a lug nut to the spark plug so you can use a socket to remove the plug. At least half of the repair shops will tell you the only way to solve the problem is to purchase a new cylinder head.
Do you have better access to plug with cover removed or does the tube stay?
Thanks for the help and good ideas. Never thought about using MIG to tack lug nut on.

try using a socket just under size that you have to hammer onto the plug preferably a six point use extention on socket to hit with hammer if socket goes to deep into the tube. your other option as a last resort before you take the head off is to use a cheap socket and use a good epoxy and glue the socket onto plug. make sure epoxy has set for complete hardening time one of these methods should work if plug is not completely seized in head.

try using a socket just under size that you have to hammer onto the plug preferably a six point use extention on socket to hit with hammer if socket goes to deep into the tube. your other option as a last resort before you take the head off is to use a cheap socket and use a good epoxy and glue the socket onto plug. make sure epoxy has set for complete hardening time one of these methods should work if plug is not completely seized in head.

Thanks. Will Try. Still firing but missing more and more. Need to replace the plug. I am gussing that when(if) I get the plug out the thread will come out too. Have to see if I can find a Helicoil with an extension to reach down the hole.