Most people who just replace rings, wont take apart the whole motor, unless you pay for it to be. You dont have to take the crank out and all that jazz, just pull the head and drop the pan.... if it is constantly smoking at idle, and driving it is most likely rings, valve stem seals will only smoke on decel, or when the engine produces a lot of vacuum, or if it sits for a while idling and you take off, it will usually puff smoke.