giving_tr33

I'm trying to edit some moves for my USUM ROM through pk3DS and while I have no problems making small tweaks to moves, if I try to change the effect of the move it won't behave properly. Examples that come to mind are me trying to turn Whirlwind into a Dragon Tail clone with the same parameters and effect number as Dragon Tail, but when I try to use the move in-game it won't force the pokemon out. Or trying to turn Memento into Parting Shot with all of the exact same parameters, but my Pokemon won't switch out. Same thing happens by trying to turn Parting Shot into a Dark-type U-Turn. I've read about people editing the code.bin files to edit the actual move code and I think I need to do that in order to make the moves work? I just have no idea how I'd go about doing this, or if that's what I even need to do. Any advice on what I need to do to start would help tremendously.