You can add Kerberos principal names to the eDirectory users using iManager:
In iManager, click Kerberos Management > Edit Foreign Principals to open the Edit Foreign Principals page.
Specify the FDN of a valid user object or use the Object Selector icon to select the User object reference.
Click OK.
Specify the foreign principal names and click Add .
The principal name must be in the format principalname@REALMNAME.
To delete the foreign principal name, select the name and click Delete .
Click OK.