impossible to update instruments

Hi,

I have been trying several times to update the instruments list of garageband through the update software of my iMac.

But guess what? The download bugs after 600 MB (or so) on 1,2 GB download that takes hours!

I get nervous, can someone help me and tell me where and how I can download instruments for garage band 11 version 6.0.5 (428.5)?

Thanks in advance.