Actuator fails to spring into place


The actuator fails to spring into place
I recently had an aftermarket stereo installed. When the tech put my console back together he neglected to lock the shift *** into place on the shaft. So, today while driving it came off the shaft, I got it back on but this evening while investigating it the button you push in to shift went flat. And doesn’t spring back into position. Has anyone had this happen to them? And if so, how do you get the shift *** open to work on it, and repair it?