Changing ATF
What year and model truck do you have?
If your TC does not have a plug, then the recommended method of ATF exchange is to flush it. Many local shops can do the whole ATF exhange for you these days, costs about $60 bucks or so around my area.
To flush it yourself, you can pull off the tranny cooler return line, using a procedure similar to the one described in this article:
https://www.ford-trucks.com/articles...hangingatf.php


