searched how to drop pan on my automatic 4r44e and have 1 question.

Ive seen some people install a drain plug how did they do this?

 

Pick the lowest point in the pan, weld a nut on, you probably will not be able to tap the hole in the pan, there isn't enough material. Get a bolt, making sure that it is the proper length.

This is a guess, my advice is to use the search button.