I always felt like my string were too high from the frets..
Debating spending money on tools and attempting to do it myself or spend $50 and get a pro to do it.
should i attempt it or just get it done by a shop?
Go for it yourself ... slowly
Nylon strings are quite "fat" (compared to steel guitar strings), so no need to buy a whole bunch of files you're never going to use.
The grooves in the nut can be deepened with a hacksaw blade used
VERY gently, a "junior" blade for the two outer strings, a "regular" blade for the two inner strings. If you use a second "regular" hacksaw blade flat on the fretboard under the strings this'll give a good guide as to how far down you can go ... you ideally want to just kiss the "spacer" with the cutting tool.
In the unhappy event of going too deep, don't panic, just glue a thin strip of plastic food packaging (yoghurt pot etc) in the slot ... if necessary re-file again slightly. My experience suggests that "just too far" is one thickness of yoghurt pot
The slots in the nut need to be wide enough to allow the strings to slide easily without being so wide that they might rattle (and cause buzzing). Also the slots should be slightly deeper on the machine-head side of the nut, again to prevent buzzing.
Virtually any error can be recovered with a drop of superglue and a strip or two of plastic, so don't feel shy about having a go.
My Kala KA-C has been re-worked a couple of times, first to properly accommodate the original strings, then when I fitted a set of low-G Aquila "reds". I can see the traces of the work with a magnifying glass, but only because I know it's there, I doubt anyone else would notice unless they were really looking for it.
The saddle just pushes out to the side, you don't even have to de-tune the strings. Be careful when you sand it that you keep the sanding straight and even. It's worth drawing a pencil line across the saddle so's you can judge if your sanding it square or not. To lower the action at the 12th fret by 1mm you need to remove 2mm from the saddle, so it's not nearly as critical as work at the nut end! Again, in the unlikely event of "over doing it", a strip or two of plastic in the bridge-slot will raise the saddle back up to where you want it!
To quote Pete Seeger ... "Take it easy, but take it!" :music: