I cant seem to find the answer to this: Is it possible to change signing-key but still use the same packagename? So that the people who bought my app can “re-download” the app with the new key, from the same Google Play page.
The background to this is that I want to extend my signing key to more then 25 years I have set now. Maybe this is enough but I dont want to be put in a situation where the key expires.
If this is not possible, could I remove my current Google Play app and create a new one with the same packagename and another key?
No. If you have an APK signed with a signature and containing a package name installed on a device, any subsequent apk with the same package name must have the same signature.