This guide will help you install the C Stick. The C Stick is the yellow joystick. This guide should be helpful if the C Stick has gone rogue.
Place the controller (buttons down) on a solid surface.
Remove the six 9.2mm Tri-wing Y0 screws that hold the back panel in place.
Gently lift the back panel up, separating it from the front panel.
Grab the Z-button by the peg with tweezers and lift it out of the controller.
Carefully unhook the cable that is looped around the peg.
Lift the circuit board out of the controller.
Use your fingers to grab the two sides of the connector and gently wiggle out.
Grab the yellow cover by the base and pull it off.