A/C pressure switch how to remove and install

The A/C was not getting very cold so I went ahead and had someone check it. I was advised it was possibly the compressor. So I changed the compressor, expansion valve, dryer and evaporator and had them pump it down and add the correct amount of Freon. Now the air conditioner gets a little bit cooler than it did but it still will not get real cold on a hot day and does not sweat back out of the drain pipe. Could you tell me how to remove and install the pressure switch? It would be greatly appreciated if you could help me diagnose further what issues I need to attend to. Thank you.