unable to upgrade to beta 17

hi
I have a himedia q5 android media player with kodi version 16.1. kodi was installed in the box when I bought it (in Thailand , use in USA ). I have upgraded a couple times in the google play App Store. I want to try a beta version 17 and with different install methods either get error app not installed or
There was a problem parsing the package

i did not uninstall the 16.1 in fear I may not be able to get 16.1 back on. plus the main menu. in the himedia has a large kodi button. I’m thinking if I uninstall That button won’t be there

any suggestions to ‘upgrade ‘ to a beta version ? will I need to uninstall the existing kodi ?

thanks