Well first of all dont install mods midgame. SO what if I, like everybody should start a new game with it? Stop talking already. if it works it works. The modding community would be nowhere as of today with people like you thinking nothing is possible out of the ordinary
So I need to create weapon animations (visuals) for my new mod, I suppose it cant be that hard, however I have no clue which software to use, as the final file has to be a nif file.