I am trying to implement a password change for a WISP that I manage. I know that I can push firmware updates from the Dude. Is there a way to push a configuration change such as a password change to all my Mikrotik devices?

With The Dude, there is no way to mass push config.

I recommend checking out Unimus - it will do this with a few clicks.
(create a Mass Config Push preset, select devices, push)

Otherwise, you can always script this yourself using TCL/Expect, or Python.

Thanks, Tomaskir! I am checking out Unimus now.