There are a few reasons you may need to take apart your ps4 controller. It could be that you have spilled liquid on it and would like to clean the insides faster, or maybe you are trying to fix an issue with the controller. Whatever the reason, you can easily do this with the right tools. It is important that you take your time and do not rush as this will cause your controller to have more issues.
Start by removing the screws from the back of the controller. You will hear cracking noises but that is normal as these are the plastic clips being separated. Make sure to remove the screws with care as they are small and can easily damage your circuit board. Once the screws have been removed, you will need to turn the controller over and place it on a flat surface.
Using a plastic pry tool, gently insert it into the crease that separates the two halves of the controller. Slowly work your way across the seam and remove the retention tabs on both sides of the controller. Once this is complete, you will notice that the top half of the controller is loose and held together only by the ribbons attached to the circuit board.
If the controller is still having an issue with the joysticks, then you will want to use a cotton swab soaked in distilled water or isopropyl alcohol and gently wipe around each button and in the creases on the body of the controller. You should also use a dry toothbrush to clean out any nooks and crannies that are difficult to reach.