Need to configure Netbackup AIR

No need for that - I think the tech note is just taking you through the process of two new setups.

On the main site just add the remote site details to the Storage Server configuration (servername, de-dupeusername and password) and then create an identically named SLP on each site

The Main site will have backup and replication stages (the replication must have a fixed retention which will control how long the images are kept on the remote site) - the remote sites SLP will have the import phase which uses target retention.

That should be all you need to do.

The step-by-step instructions only need to be followed if you do not have MSDP with diskpool and STU configured yet.

So, you should be able to skip to step 5 and create SLPs:

5. On the OC site master server, go to “NetBackup Management” -> “Storage” -> “Storage Lifecycle Policies” -> New