63 Signet Drivers Mirror Replacement

You may have the wrong mirror. The '66 and earlier mirror have a removeable control that is larger in diameter than the '67-up version (which has a crimped cable/control connection), Check the diameter of the control hole in the door before you go to the trouble of trying to make this mirror fit. If it's control is the correct diameter removeable type for your door, yes, you have to remove the cables from the control, feed everything through the door skin and then re-attach it. Trying to remove the '67-up control will usually result in a broken control or damaged cable.