An increasing number of people ask for this kind of job, but it's usually on electric or acoustic guitars, and not for classical guitars such as this one
Normally guitars allow for some degree of separation between strings, and here I'll show you how to take advantage of this. Greater separation is advantageous for people with large fingers, like me. Also, both nuts will be easy to replace, which will allow us to change this distance almost immediately.
It's important not to forget that we can't divide the total length of the nut by the number of gaps between the strings. The thing that has to be equal is the distance between the strings, and since some strings are thicker than others, we need to take this into account when making calculations. There are special measuring devices for this kind of operation as shown in the video.