Is there a reason you aren't hosting the APK on Google Play, Amazon, or one of the other platforms?
If not, doing that would let you publish an update that everyone can download.
If you need help getting set up on one of those platforms, post what the hurdle/obstacle is and maybe we can help get you set up.
But to your question, it needs to be done manually. If you are using the same package name, they don't need to uninstall the old version. just install the new version over it.
And good luck with the Fantasy Cricket Business!
oh... I think I just realized why it may not be on Google.