How can I choose a specific location for Logic's 40GB of additional content?

I have an SSD onto which I've installed the operating system OS X 10.10.1, as well as my applications. I also have a much larger and much slower internal HDD for storage and other rarely-accessed files.

I use Logic X for audio editing, and I have historically enjoyed having access to the 40GB of instruments and sounds referred to as "additional content" optionally available for download from the program menu.

When attempting to download the additional content, Logic informs me that there is not enough free disk space to download all 40GB, which is just as well, because even if I had the space I would prefer that these 40GB of additional content files remain on the HDD rather than the SSD.

How can I specify an alternate location in which to keep Logic's 40GB of additional content files?

If there is no such setting, would it be possible and/or advisable to create some kind of file system pointer for the additional content's folder, à la unix-style symbolic link, across different physical media? (or at least to another partition on the same physical disk?)