I let it run out till it didn't run out really bad. I didn't wait for it to stop dripping out, but when I uncapped it it gushed out pretty bad.

Mind you, that you shouldn't drive it first as it will build up pressure and do the same thing. I hadn't driven mine in a long time, like days. Then started it up, got under neath, opened the fill plug, and it had so much pressure at least two quarts gushed out before slowing to a slow drizzle. Then I capped it off and let it settle for a few hours. I started it up again, had my wife shift through all the gears then into park and tried to pump some fluid in it. It wouldn't take a drop more. That shop had pumped so much fluid into it it was about to burst.