(HOW TO CHANGE EVERYONE'S PASSWORDS)
Run the below from a Windows Powershell to change all passwords. Change the query to match your path. Change NEWPASSWORD to the password you want.
To test the DSQuery path is pulling the users correctly:
DSQUERY user "OU=users,DC=cognetic,DC=com"
To change the passwords and set must change password to no:
DSQUERY user "OU=users,DC=cognetic,DC=com" | dsmod user -pwd NEWPASSWORD -mustchpwd no