Hi there!!!

I just had all four of my side marker lights and two blinkers "smoked" at a custom body shop. I know the blinker lights have to be slid forward to be removed, and I was very clear when I told the people this. My passenger side blinker appears to have a knick in the plastic, and won't hold now. The rear driver side reflector/light is now loose and won't hold on one corner. I told them the corner lights have to be removed by putting your hand behind the fender, /'d not popped off with a screwdriver. Is that correct? What's the correct way to remove the corner lights, and is this small knick in the blinker the culprit for it not holding? I just want to get all of my facts straight before I blow a gasket on them tomorrow. Thanks in advance!