When do i change the differential oil on a 2005 corolla with 60k on it and where is the drain plug located.?

well, you don't have to change the fluid. I work in a transmission shop and I rebuild differentials and transmissions. honestly you can pretty much have a car go it's lifetime without changing the differential fluid. trust me. but if you really want to do it. you're car is a front wheel drive so you have to pop the hood and find the transmission, on the rigtht side of the engine and there should be a hex or square plug, you can use a crecent wrench