I have an 07 4runner V8 that uses Toyota WS ATF - supposedly, this is a "lifetime" fluid that doesn't need to be replaced. However, if one wanted to drain and refill, how to do it? The FSM only shows you how to check the fluid level using the fill plug and overflow plug. I don't believe you can drain the fluid using the overflow plug. Is there another drain plug somewhere? Or is the only way to service this transmission is to do some sort of flush? Thanks.