Where's the drain plug on a 700r4?

Put a little too much atf in my '85 GMC. It's just above the checkerboard. Not familiar with chevies in particular, would this damage it fast? Any tricks to draining it? It shifts fine but I do know if it's overfilled it could kill the trans. It's got a slow leak where the speedo cable enters so it will leak over time. Trans has 182k miles on it.

Thanks guys.

There is none, if you re worried, get some out of the cooler lines.

you could pull the dip stick and use a 3/8 or 1/4 in plastic pipe and vac the trans fluid down to the correct level. (make sure to measure the trans fluid when the trans is hot in park and on level ground to get a proper reading) 463

Thanks guys. I got it taken care of.