This is simply a text file of notes I have collected from the web and from my own tinkering for the editing of the the head morph via altering values using the Trilogy Editor by Karlitos' (Trilogy Save Editor at Mass Effect Legendary Edition Nexus - Mods and community (nexusmods.com))

Most of the Scalar and Vector notes came from outside sources, with my own observations. The Offset Bones I ran through myself by editing and checking in game, again with my observations.

It is a simple space/tab formatted text file with breakdowns of each part I found useful and worked when fooling around. 

The lighting in Mass Effect Legendary (and in the originals) can *greatly* effect how some of these edits would look. I would recommend that you Export your Head Morph as you have it now to a file and then tinker going forward. That way when your creation turns out fantastically awful, you can reload your last Good Shepard Head.

Thanks goes out to Karlitos for the Trilogy Editor, without that fine thing, we would be stuck with boring colors and plain faces. Now, giant overbites and weird green hair with red eyeballs!

Updated 2.0 - Split into two files. Redid all the hair notes after ratting around the original ME2 PCC files with ME3Explorer. Still brute force by changing models and textures in the editor, but a bit more organized. Fixed some crappy wording in the main tweak file for the face model Offsets and changing skin/hair/lip/eyebrow color.

Updated 2.1 - Added the Ashley Hair. Also, I added a *rough* guide to looking up the values for the Textures and Models by accessing your original Mass Effect files. I am damn sure there are names that may not work or cannot be found because of the differences when upgrading the games to the Legendary. But, it is what's available for right now.

Updated 2.2 -  Put in basic Face Texture names for swapping the Diffuse and the Normals and a updated the notes in the main notes file on the naming conventions. Now that the ME Modder is out for the Legendary edition, most of this can be done by simply replacing the default texture called out in the RON file with an overwrite in the game files themselves with your personal texture file. (Probably a bit harder, but on principle...)

Updated 2.3 -  Fixed dumb mistake on HED_Scalp_Spec labels in notes. Durr. Used the UE Viewer  to page through the ME2 PCC files, added/corrected a couple of things. Couple of extra models and alternative models. Also used the MassEfffectModder to look at the textures and did the same.

Updated 2.4 - Added the Eyelash entry for the Iconic Femshep along with note about swapping Scalp Textures with the Mohawk.

UE Viewer:
UE Viewer | Gildor's Homepage

MassEffectModder:
GitHub - MassEffectModder/MassEffectModder: Mass Effect Modder (MEM)

Note: I should mention, these are all based on altering Female Shepards. I made 4 different characters (all femsheps) with different heads and hair and played around with their head morphs.