I've just refiled my Nighthawk nut.
Real tools are needed for that, it's a real investment.
It's not a waste of time and money, your instruments will have a perfect set-up.
I've got three files for 10-46 string gauge, it works for other gauges if you use them well.
If you use a set of 13 thicker, maybe files for acoustic guitar will be needed but you can manage it with the files I've got.
It's not a lot of money for what you want to do, you'll maybe do it wrong with bad tools, and all the money you saved and much more will go to a luthier instead.