Change admin password using shell script

[bidyut]

I'm creating a training environment using pfSense on AWS. I need to launch the AWS Marketplace AMI and then configure it automatically before student gets to it. I'm planning on running a shell script over SSH.

How do I setup admin password using the shell script instead of using the UX>

[dragoangel]

Only: passwd username

[kiokoman]

pfSsh.php playback changepassword admin

[bidyut]

"sudo pfSsh.php playback changepassword admin" worked.
Thank you very much.

"sudo passwd admin" - goes through the motion but admin password doesn't change.