Removing a side mirror

It's a 1973 Dart Custom. I'd like to remove the side mirror for painting reasons. Everything is removed but assuming I need to pull the the cables plus toggle through the hole left by the mirror, I will need to remove the square clip from the threads on the toggle body. Is there a technique for removing that? Or, is there a way to separate the cables from the mirror body at the opposite end?20241019_111809.jpg