I am trying to remove 2 rear Surround Sound Polk Audio speakers that are mounted in the corners of a room about six feet from the floor. These speakers are at least 10 years old and were a part of a set of 2 front, 1 center, and 2 surrounds, and perhaps a woofer. I want to relocate the speakers to another room. I cannot determine how to remove the 2 corner speakers. There is a lable on a the top of a circle about the size of a 50 cent piece the says something to the effect of moving the red arrow to the groove. So, I am assuming that you would just move it away from the groove in order to remove them, however you and turn this part with any tool that I have tried. I do not want to damage the speakers or the wall mount as I want to reinstall them in the other room. Can anyone help me with this problem?