Socket size need remove spark plug - 2002 Mitsubishi Eclipse

SOURCE: Spark plug cable is broken.

Get a suitable pair of plyers, grip the plug wire where it is thick, on the jacket that is on the plug, and pull hard. Maybe twist a little, but not sideways, as you risk breaking the plug. It should come off.
What may happen is that you will get all the rubber, and the metal locking tap will stay on the plug. Then use a pair of needlenose plyers to remove it.

The plug size is usually a 13/16 or a 5/8.

Don't really worry if you break the ceramic part of the plug, you can just remove what is left with the socket, and put in a new plug.

SOURCE: How do I remove sparks plugs from a 2002 lancer,

There are 2 standard sizes for spark plugs, and you should use a "Spark Plug Wrench/ Socket"
Either the small version, which I believe is 5/8ths inches, or the large version, which is 3/4ths inches. Either one will cost a few dollars, but will help prevent you snapping the ceramic part of the plugs off.
There are other specialized sizes out there but they are specialized for specific uses. Not for cars in general.

The hardest part is removing the wire and boot without damaging the wire/plug connection. If you have compressed air, its a good idea to blow any accumulated crud out of the plug well, perhaps with the aid of a long brush, before removing it.

You need to pull straight up following the angle of the plug, BY THE BOOT - NOT THE WIRE. This can be difficult on old wires which are stuck to the plug. You can twist the boot rotationally to loosen it

Guide the socket over the exposed plug. Again, keeping a straight line on the plug and apply steady pressure counter clockwise to unscrew it. Once past the initial resistance you may be able to remove the handle and unscrew the rest of the way by socket (& extension) only.

To replace the plug (or new one) Set the plug into the socket. The foam liner will hold it in. Angle and move the plug in a straight line (same angle it came out) down towards the hole by the socket and extension without the handle, and - finger pressure only - carefully start the threads. I usually start by turning counter clock wise first to feel the threads seat squarely before trying to go clockwise. You should be able to wind the plugs down almost all the way in without force.
When you reach the bottom, attach the handle and snug up the pressure gently, then give it approx 1/4th or more additional turn to lock in. A little crud falling in the threads may require a little more help to wind it down, but never force it as the threads may be crossed. ( Then you ll have some fun)

Does this help?