There’s a whole discussion here about whether it’s possible or not, and some claim it is but they never post handy tutorials on exactly how - they git go “oh… alchemy”. Why can't demons create physical changes?
I have made changes but only within my potential per my DNA. I’m currently working with the MAP team to see if I can affect my epigenome.
This post has the best advice I have seen so far - adapt “taller” with what you want and try it:
This is several posts merged to keep the advice all together under one discussion Spell or Demon [Entity] to increase height / grow taller? - #18 by Mulberry