Mine is right in front left of the snout, looking at it on the motor. A 6mm allen setscrew looking thingy, IIRC. I did the same thing, used a syringe to suck the old oil out. I went to a Chevy dealer and got 8oz of super charger oil, cost about as much as a quart of motor oil. It has a narrow tip to fill with, and as mentioned earlier fill it up till it runs out.

Hope that helps, Dan