Belgium 2012 re-uploaded + enhancement package

Hi, I'm a newby here. I've some questions about the installation. I've download the 3 parts as .rar. I understand that i've unrar the files. Must I unrar them all or only part1? Or should I unrar part2 and part3 also?

And how i've to install them in FSX? (FSX/addon scenery/belgium 2012) and then activate in the library?

(I'm working with W7 64b, i7 3775, 16gb)

Thnx in advance,

Regards,

Casper