I wanted to do the same thing – install the Kontakt 2 player and all that stuff on my system disk (I'm on Mac, btw) and the library on my dedicated samples disk. I couldn't find any hint in the instructions whether this was possible.
So, I emailed Garritan support and was told (very quickly – thanks! ) "You can not separate the files in the Strad. All files on the disk should reside in your main applications folder."
However, lo and behold, halfway through the installation process, I did get an option to specify where I wanted to store the library! So, I selected my samples disk, authorized and it worked perfectly – player and VST & AU plugs on my system/apps disk and the library on a separate one.
Well, not so on a PC - I got no opportunity to install the library on another drive apparently there is no option on Windows.
I did transfer all the Strad V2 instrument directory onto my Samples disk (H: in my case) and could load the library into the player.
I also renamed the original directory C:\Program Files/Garritan Stradivari Solo Voilin just to test and found that on opening K2player it will not find the changed location. I have to manually "Load" it into the player
So now the decision is do I clutter up the Op system drive with programs AND samples or do I manually redirect everytime I load it.
OBTW I've tried this only in stand-alone mode so far
After the install - (and after you've copied/moved the files to your sample drive (H: for me), just go into the "info" tab and at the bottom of the dialog box where it says "Library Installation Path" just browse to the new directory and select it - seems to work fine