Guys help me out

[1985pickup]

So I want to change my transmission fluid in my 1985 toyota pickup 4x4 22re because I'm not sure the last time it was done. So I looked around online and didn't see anything that made it crystal clear for me. I think I found the drain/ fill hole but I want to make sure before I start wrenching. Any help is greatly appreciated. Here are some pictures of my transmission.

The drain hole is on the bottom? 15/16
But what one is the fill hole I'm not quite sure.

There's hole on the passenger side that's also 15/16.
Sorry if its a newb question thanks for the help.

 

[1911]

The drain and fill holes are 24mm bolts (or were stock). The 24mm plug on the bottom is the drain hole. The one on the driver's side in the middle is the fill hole; it looks like someone has replaced it with a 10mm socket head plug.