To pull your ash tray out you're probably going to have to have the transmission in 1st gear as you can't fully pull it out when it's in park. So put it in 1st, pull the ash tray out as far as it normally goes, then stick your hand underneath and push up on the metal retaining tab, and pull it the rest of the way out.

The fill plug on the bottom of the pan is fun. You need to have the car in the air so that you can get underneath it. It also needs to be level, warmed up and running. Have the low beams and/or A/C on while you do this. Then pump new ATF into the pan until you get it running back out of the fill plug. Re-install the plug and you're done.

Though you should drop the tranny pan, get a new pan gasket, and a proper BMW tranny filter. The aftermarket filters don't always fit quite right, and they also can flatten out (as they don't have the ridges molded into them that they should) and cause oil starvation and kill the tranny.