the part from sears that they are talking about is EZ Out..and one guy used liquid wrench and patience...here is the link

"thanks for the replies guys......was able to take out the remaining piece of the spark plug by applying liquid mechanic and trying to twist it off slowly.....did that for about 30 minutes and it finally came off....."

^^^^quote from the thread bout liquid mechanic

link

http://www.g2ic.com/forums/showthrea...ken+spark+plug