[KKS] Why won’t 7zip install the split files properly for Koikatsu Sunshine EX, did I do something wrong?

I’m new to split files and I’m not sure why the files aren’t installing😢! I got them off of Google Drive without a subscription, and I installed 7zip before uninstalling Winrar, whoops😟! I don’t know if 7zip is installed properly as a result and I don’t know what to do😵‍💫!