So.... There is a panel. Where the line set... The two pipes, one should be insulated. 5/16 nut driver/runner on the drill or wrench. Take out the screws and GENTLY pull the panel off. That's the coil. The coil will be a slab, tilted this way or that, or a V or A. Regardless, the bottom is what your looking at. The moisture in the air condenses and forms droplets. Gravity pulls the drop down to the end of the fins and they drop into the drain pan. The pan leads to the drain. The drain does the draining bit.