Logic Pro X Download LPX how?

Hi folks,

So, I have that Mac Pro (2x2.66 Xeon) sitting in my music refuge and I'd like to install LPX on it.
There's no suitable internet connection avilable at that place (just my slow-ish mobile connect which has limited data throughput per month, too), so I'd like to download things at home.
How do I do that? I can't do it with my old Macbook as the AppStore is telling me the OS is too old (which it is, but I can't update it) and I wouldn't happen to know about any other way to get it but from there.
All I want is to download Logic plus additional content at home, slap it onto an external drive and take that with me.
This is possible with every other music software I'm using (sequencers, various plugins, etc.), so Apple must offer a way for Logic customers, too. Just how?

Fwiw, I usually download things from a Windows machine. Is that even possible with LPX at all?

No, you can only get Logic Pro X 10.4.1 from the App store, which requires a somewhat newer Mac, somewhat recent Mac OS, and an internet connection
Can you take the drive out of the Pro, use a USB disk housing to connect it to the MacBook, boot from it, and install things from it? I guess there could be some issues with the Apple account verification.

Otherwise, you might just have to take the Pro to a place that has a good connection.