“Open the Construction Set and load Morrowind by clicking on "File" and then on "Data Files,"then select Morrowind by double-clicking on "Morrowind.esm" and clicking "OK."
Once Morrowind has finished loading, click on the "NPC" tab in the "Object Window." Search for the NPC named "player" and open the properties window by double-clicking on it. Choose the race you will most likely play - the reason for this will be explained later. In the right-mid part of the window, you will see the "Add Animation File" button. Click on it.
Now you will need to browse to the folder in which you've put the downloaded files. You'll see you can only select "Complete.nif" or "xComplete.nif". The third file, "xComplete.kf," is not visible here, but it is still needed, so please don't delete it. To replace the animation file, select the "Complete.nif" file, not the one with an X in front of it. Click open. At this point, changing "player's" race will reset the animations to the default and you'll have to go through the above process all over again if you want the animations to work. Thus, its best to decide which race you plan to play before setting up the mod.
There should be no missing texture errors for this file - I haven't encountered any - but if there are, please ignore them, and press either "Yes" or "Cancel" for "Yes to All". Now press the "Save" button to save the newly entered NPC data. After that you will need to save the Mod itself by clicking "File" and after that on "Save". Type any name you like and save the file.Now you've made your mod!”