when i don't know of any tutorials but i can tell you how
or at least how i know too, the only thing with this way is that it will replace the original hair
you will need
s3pewhat you do is open up s3pe, then file - open
find the file that you want and then click open
now what you have to do is go threw the image files and find the ones you need, so the alpha,control,specular, and such
you can look at them by clicking the view button at the bottom
once you find the one you need click on it and then go to Resource - Export - To file
do your editing thing then import the files back where they were
once all the files are replaced go to file - save
and that's it