Plex - adding third party channels.

I have successfully installed Plex from the admin interface.  I've set up the folders for scanning and the system stems to be working correctly.  I've placed my music there, and can access it from external plex players.  I did the default installation. (I say that to say it appears to be working fine.)

I would like to add third party channels. 

Is there away to use the ReadyNAS interface to drop the files in to the proper folder (with in the Plex install)?

I have temporarilly enabled SSH, since this appears to be the only method.  I have access, but it would appear the admin account does not have WRITE access to the proper folder.  How do I change permissions, if this account doesn't have them already?

Thanks in advance for any info.

Rich