Yeah whoever wrote that program put the button in the wrong place. It doesn't totally make sense. You would think that you could click on the animation sequence in the "Model" tab, then press DEL on the keyboard, but for some reason it doesn't work. Instead, if you maximize the window, then click on the orange ball with streaks to enter "Select Node and Animate" mode, then click on the squiggly red and black icon that appears in the lower right hand corner of the "Edit" tab, it opens a menu with a "Delete" button for animations (as well as some other things).
It will then give you a popup asking whether you want to "also delete keyframes." If the model is Reforged, sometimes those models have overlapping animations. So then deleting Stand - 2
will delete the data for Stand - 3
if they are the same and you choose to delete keyframes. That could mess up the file. But if you don't have repeat animation headers spanning the same timeline in this way, and have distinct timelines for each animation sequence (like how all MDX files on the 2003 game were), then in that case "Also delete keyframes" is always good to do, since it will reduce file size.