2008 Toyota Camry LE V6

This is generic, but the low side is the larger of the two lines, the line that goes through FROM the evaporator, the gas flowing to the compressor. The smaller one goes from compressor to condenser, in front of radiator. In my Corolla it's even marked "LOW"

One more. See that it goes through firewall? that is to go to evap. Remember, general rule, bigger line, low. Smaller high. I don't know what you plan to do, but please do not release R134a gas in to the air we breathe. it's highly illegal and just plain wrong. Good luck with your repair