If your Nintendo Switch is suffering from the now famous Joy-Con Drift issue, you can look into replacing the Joystick. These Joysticks are inexpensive and can be purchased online. Note that there is no difference between the left and the right Joysticks; both are the same and will work in either the left or the right Joy-Con.
You will also need a few tools to open up and disassemble your Joy-Con. These tools can also be found online for relatively cheap. They often come in a kit with a bunch of other tools. The picture below shows you what you’ll need for the Joy-Con specifically.
First, use the Tri-Wing Y2.0 screwdriver to take out the 4 screws of your Joy-Con.
Carefully open up the Joy-Con. Be careful not to pull the wires too hard.
Next, use a pick to carefully pry out the battery. The battery is held in place with a couple small pieces of tape. Keep the tape in place; later when you’re done it will still stick to hold the battery back in place.
Below the battery, you will see 4 screws. Remove them carefully with a phillips screwdriver. There is a 5th screw near the bottom of the Joy-Con as well.
Carefully lift the plastic cover to expose the electronics underneath. Ideally, you should also try to gently pry out the battery connector to disconnect the power to the Joy-Con. In my case, I found it wasn’t coming out so easily, so instead of forcing and damaging things I decided to just keep the battery plugged it. Not ideal and chances are if you touch something wrong with your screwdriver you can shortcut and damage the electronics.
Use tweezers to carefully lift up the little tabs on the connectors shown below and then gently pull out the wires. Then use a phillips screwdriver to remove the 2 screws holding the Joystick in place.
You can now lift out the Joystick.
Get your new Joystick and place it in the Joy-Con. Now work in reverse to assemble your Joy-Con back together.
Next, you may need to calibrate your new Joystick. On the Switch, go to System Settings.
Under Controllers and Sensors, select Calibrate Control Sticks.
Follow the instructions on the screen to calibrate your new Joystick.