I have Sims 4 Premium Edition. Installed disk 1 but how do I install Disk 2?

I agree. I only saw a bunch of zip files as well. It is very confusing. I tried to instal disc 2 directly after disc 1 was complete and nothing happened so I set the disc aside. When I went in game, all the "extra content" that we're suppose to get with the premium edition had indeed showed up in cas and buy mode. Disc 2 never installed though. So what exactly does that disc do is what I'm wondering about. I will get a notification if anything installed and disc 2 did not.

I was also never prompted to insert disc 2 as disc 1 only downloaded via origin and completed fully. I can play my game just fine but the only content that I can really say I saw that did come with the premium edition are the animal hats and odd outfits like the hotdog and clown and a dunce looking hat as well. If there is any other content on disc 2 and others are not getting what they fully paid for like myself (whatever that may be) then I hope this issue is addressed as quickly as possible. Like someone said, we just want to play the game and have fun, not deal with the frustration. It sucks that I can barely download the game or load it up before already having problems with it.
And where's the soundtrack at? Like, I don't understand anything anymore lol