/jp/ - Otaku Culture

so im going through the pdaft install guide (im not the anon asking about mods) im on step 4, ironically the mod pack. pic related, the files have a .001-.008 extension. i assumed i needed to remove the extra numbers so theyre just .7z files. i tried to extract the one i renamed but got the error in pic related. i consider myself to be pretty computer savvy but this doesnt make sense. when i downloaded the mod pack, i clicked "download all" and google drive zipped the files again. am i supposed to just download them one by one? did google drive zipping them together fuck something up?