Actually easy to say.
I mean, just take a clean copy of V15 server files ->
And add to it the functions, features, etc.
Until you reach a V19 feature source.
In order to do this, you must be atleast an "average" programer/developer.
Cause you'll need to edit the source for that.
If you cannot edit the source, means you are not yet ready to start this project.
you might want to improve your experience first.
Anyway, good luck with that.
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