Answering my own question since I discovered a solution. Without a custom recovery (like TWRP or CWM) you have to use one of the Android apps for flashing .zip files, like Flashify, Rashr, or Flashfire. I used the latter & it worked a treat. Didn't try the others but believe they would also work.
No indication FF was working but Q10 rebooted & upon restarting Viper4Android shows up as an installed app w/audio driver already installed. Keep in mind this is only for rooted devices (& rooting voids warranty).