Not all schema changes are allowed. See Disallowed schema changes for change restrictions.
Web administration
If you have not done so already, expand Schema management in the navigation area, then click Manage object classes. To edit an object class:
Select an attribute from the alphabetical list of Available attributes and click Add to required to make the attribute required or click Add to optional to make the attribute optional for the object class. The attribute is displayed in the appropriate list of selected attributes.
Repeat this process for all the attributes you want to select.
You can move an attribute from one list to another or delete the attribute from the selected lists by selecting it and clicking the appropriate Move to or Delete button.
You can view the lists of required and optional inherited attributes. Inherited attributes are based on the Superior object class selected on the General tab. You cannot change the inherited attributes. However, if you change the Superior object class on the General tab, a different set of inherited attributes is displayed.
Command line
View the object classes contained in the schema issue the command:
ldapsearch -b cn=schema -s base objectclass=* objectclasses
To edit an object class using the command line, issue the following command:
ldapmodify -D <adminDN> -w <adminPW> -i <filename>
where <filename>contains:
dn: cn=schema changetype: modify replace: objectclasses objectclasses: ( <myobjectClass-oid> NAME '<myObjectClass>' DESC '<An object class I defined for my LDAP application>' SUP '<newsuperiorclassobject>' <newobjectclasstype> MAY (attribute1> $ <attribute2> $ <newattribute3>) )