Changing Brake Pads To Eliminate Brake Squeal on a Juiced Bike Without Removing the Rear Wheel 

I tried everything we were told to do to get rid of that hideous noise coming out of our brakes. It’s like a cat was dying every time I got to a stop sign or red light.
I didn’t know what embarrassment meant until I experienced this issue new out of the box.
I put the cotter pin in the wrong way. The hoop side should be towards the outside of the caliper and other end facing the spokes.
I honestly don’t know why I didn’t think to remove the adapter plates and caliper as a single assembly from the frame altogether (two Allen screws in the yellow frame). Doing it that way may be even easier! Theoretically, it wouldn’t require realigning the caliper to the rotor.