Have you looked at man usermod? -p flag in particular.
Shame on me, indeed. It has been a game:
#!/bin/sh
PASSWORD=$(echo "my_new_password" | encrypt -b 6)
usermod -p $PASSWORD root
Thanks.
--
I must not fear. Fear is the mind-killer. Fear is the little-death that
brings total obliteration. I will face my fear. I will permit it to pass
over me and through me. And when it has gone past I will turn the inner
eye to see its path. Where the fear has gone there will be nothing. Only
I will remain.
Bene Gesserit Litany Against Fear.