Configuring PAM authentication is typically done during the deployment process so I wouldn't think you'd need to do it again, though I personally have only done new deployments. If you did it need to do it again it would be a matter of setting in sasauth.conf the methods=pam instead of methods=pw, and potentially setting up /etc/pam.d/sasauth again, so you could take backup copies of those files to reference just in case.
Installation Note 49432: Configuring PAM on Linux to authenticate through SAS® against Active Directory or LDAP
https://support.sas.com/kb/49/432.html
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Greg Wootton | Principal Systems Technical Support Engineer