Users are one of the few things that are still using CPMI (i.e. they are not available through the REST API).
Which means using dbedit.
From the management station (or domain), you should be able to use dbedit -local and get a prompt.
From there, you can issue the command printxml users
However, this output will not be in a format that you can immediately "import" into an existing management station.
The dbedit commands needed to create a user look something like this:
create user USER_NAME
modify users USER_NAME auth_method "Internal Password"
modify users USER_NAME internal_password PASSWD
update users USER_NAME
addelement users USER_GROUP '' users:USER_NAME
update users USER_GROUP
From the XML output you should be able to figure out the commands needed to recreate a user.
I imagine you could script this.