What could you possibly not like about my name generator?
But fine...
"C:\Users\-your username-\AppData\Local\Cyclopean\Save_1\character.sav"
Scroll all the way down, and you should see the name there a few lines up from the bottom.
Make sure you don't change any commas or the game will not load properly.
This assumes you are in the top save slot. If it is a different slot, you need to change the "Save_1" to the correct number.