You need to locate your downloads folder for the DAZ Install Manager (DIM). Once you do that, put all the files in there, it's important that you have the supplement.dsx and Manifest.dsx files in there.
Then you can run DIM and it'll install. Well, that's how I've been doing it anyways.
I noticed some packages don't come with the dsx files, not sure how to install those. Some of them just tell you to double click or drag the file into your daz with the character you want modded selected. So I just copy them into my library and use them like that.
Maybe someone knows another way to install the ones without the dsx files??
Good luck man