what i would recomend you if you dont wish to have a hard time, is download an add on with hairstyles for ur class, and just add it directly, replacing one of the hairstyles inside (which is what i do to not overcomplicate myself You can also do the same, to take example on how to actually compile; my apologies that my answer is not AS good as expected, but im not personally a modder, just a starter
You will need to put your hair in... Code: assets\humanoid\human\hair Replace 'human' with whatever species you are adding to. You can then just overwrite your species and add the hair to this file... Code: \species\human.species Again, 'human' is whatever species you are adding to. The relevant lines in the *.species file are... Code: "hair" : [ "male1", "male2", "male3", "male4", "male5", "male6", "male7", "male8", "male9", "male10", "male11", "male12", "male13", "male14", "male15", "male16", "male17", "male18", "male19", "male21", "male22", "male23", "male24", "male25", "male26", "male27", "male28", "male29", "male30", "male31", "male32", "male33", "male34", "male35", "male36", "male37", "male38", "male39", "male40", "male41", "male42", "male43", "male44", "male45", "male46", "male47", "male48", "male49", "male50", "male51", "male52", "male53", "male54", "male55", "male56", "male57", "male58", "male59", "male60", "male61", "male62" ], // "hair2cut" "hair9cut" and Code: "hair" : [ "fem1", "fem2", "fem3", "fem4", "fem5", "fem6", "fem7", "fem8", "fem9", "fem10", "fem11", "fem12", "fem13", "fem14", "fem15", "fem16", "fem17", "fem18", "fem19", "fem20", "fem21", "fem22", "fem23", "fem24", "fem25", "fem26", "fem27", "fem28", "fem29", "fem30", "fem31", "fem32", "fem33", "fem34", "fem35", "fem36", "fem37", "fem38", "fem39", "fem40", "fem41", "fem42", "fem43", "fem44", "fem45", "fem46", "fem47", "fem48", "fem49", "fem50", "fem51", "fem52", "fem53", "fem54", "fem55", "fem56" ], // "hair2cut" "hair9cut" One is for male hair and one is for female hair. Just add your hair to the end of that list. Using merge is a bit more complicated as it doesn't play nice with lists (at least, that has been my experience).