Sorry Osage, I mis read, I thought you were talking about taking the nipple in and out. moose is telling it right. The plug should not be removed from the sidelock. I doubt if you can find enough tools and vices to get it out anyway. I tried to take one out on a Thompson New Englander once, and finally had to give up and take it to a smithy. They are in there a lot tighter than you might think.
