LDAP authentication for Isilon

We have Isilon storage (2 clusters ) with mixed node types - NL400, NL410,  X400 and new a40 nodes on which we are planning to migrate entire data.

One issue, we are still using root logins and no administrator account setup, or any integration with LDAP.

I haven't done this integration, its always done beforehand. Whats are details we need to do this and how can we integrate Isilon authorization with LDAP ?

Please suggest.