Where is the air-conditioning drain line on a 1995 Plymouth Voyager with a 3.3 V-6 and easiest way to clean it?

My drain has clogged up about once every 18 months since the car was new. Love the van have 100,000 mile on it with almost all of it being short city trips but I want to be able to clean this out. I am not the most informed owner so please be as specific as you can.