Jam Packing GarageBand

So I'll be upfront here. I am a complete n00b with Macs. I've owned my MacBookPro for maybe all of one month. I bought it to make music on and after being broke from buying the computer I'm just using GarageBand. Well I've decided that I need more instruments to use. I do not use the loops, at all, so there is no way in **** I'm paying $100 for a jam pack. So I've started downloading all the jam packs on bit torrent. Now the question I have is how do I install these once they're done downloading? I'm downloading these on my Desktop and I'm gonna be transferring them on a external hard drive. So how do I go about doing this? Thanks in advance.
P.S. I don't really want to hear anything about how I shouldn't download stuff without paying. I payed a few thousand dollars for this Mac and I am not paying hundreds more for a ton of stuff I'm not even gonna use. I just want the instruments. Apple is insane for trying to charge that much. Again, thanks in advance.

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Yeah...so don't discuss speeding or tax evasion either, 'kay?

Now....if you use your favorite search engine, you'll be able to find some free loops and instruments, so you don't have to worry about any legal issues. Wherever you source your loops/instruments, the dox should tell you how to install them.

Hey you know what? I spent all my money playing poker online, and now I haven't got any money for food. Dang, food sure is expensive, I want steak. The grocery store should just give me the steak because I want it and can't afford it. I'm sure they'll see the logic in that.

If they won't give it to me, I'll just steal it. I have a perfectly good reason to steal, which is that I want something but don't want to pay for it.

Hey -- stealing is illegal; you can't discuss that here!

(Again, there are some loops and instruments legally available for free in the public domain -- GIYF)