The changes on github become available on a receiver (via feeds/software) after a release build is run. You cannot update the files from box directly, unless you have a script to fetch the updated file. You can always download the file and transfer to the receiver. If you had installeld or package was pre-installed, it will be updated automatically when you perform an update. There is no need to uninstall and then re-install.
The uninstall/re-install methodology is normally what the people using OpenATV and against performing updates advise. OpenATV normally run builds nightly, so their feeds get updated almost nightly. If you uninstall a package and then re-install it, you would re-install the latest version.