I've had some success with cleaning out the oil separator box by filling it full of engine sludge cleaner (kerosene?), letting it drain, filling it, draining it, etc.....of course this is followed by an oil change, don't drive the car with an oil pan full of sludge remover. Not Good!

It's not as thorough as pulling the box off, but a hell of a lot easier, and less dangerous than accidentaly bonking the seperator drain pipe out of position. Follow up with a full inspection and cleaning of the trap, hoses, ports, etc.

Good luck! Josh