This looks like a one-off thing you need to do semi-manually and methodically. Every step of the way you need to balance the effort of doing something with a s

This looks like a one-off thing you need to do semi-manually and methodically. Every step of the way you need to balance the effort of doing something with a script vs doing it manually. How long would it take to manually make the change in all 100+ repos... vs. how long would it take to write a script to do it. Would the script be robust enough to properly make the change in like 90% of them... etc. These are things you need to ask yourself in your endeavor. You'd want to do all this work on a new similarly named branch (or branches depending on your workflow) for every repo. Perhaps write a script to validate changes to all 100+ repos on that branch. Then when all the work is done... do a massive merge.