Hey Kumarasinghe,

I've fortunately not had the chance to figure this one out but it looks like it might have to be done manually.

Source: http://support.apple.com/kb/HT6260?utm_source=dlvr.it&utm_medium=twitter

Darren

I asked Apple if they had a solution for this for K-12 (our music classes use it) and was told no, but they are looking into it (this was weeks ago).

I decided to keep old Garageband on our standard image because of this (with the new one).

Anyone make any progress on this?

Apple has fixed this with MAContent10_GarageBandCoreContent_v3.pkg and adding the premium content over it.

To download the available content:
https://github.com/erikng/adminscripts/blob/master/download-gb-content.py