Been a long time. I think a rar file is like a zip file. I think 7.zip will unzip it into the individual apk's then get the app APK installer to install the particular apk.
I got my phone the way I want and have not tinkered wit in for a few months. Pulling this out of my aged memory. Let me know if that works. If not tell me the apk's U need and I can email them to U.