91 van with 5.0L engine

I have 91 van with 5.0L engine and I wanted to change engine coolant today but couldn't find the drain plug.......I use to find drain plug under the radiator in the other cars but seems like this engine's radiator has different location of drain plug......

can anybody tell me where that plug is???

also....I'm gonna have change oil pan because it's leaking but do you guys know how hard it is in this engine???....If I have lift the engine I won't bother to do it myself but If it's simple, I want to do it myself....

thx in advance.....