I've got my app approved a while ago and used the * provisioning profile so I created somehting like:
com.mydomain.MyApp
but now I have the necessity of adding push notifications and I can't due I am using the * provisioning profile and it needs to have its own app ID and profile.
How should I proceed in order to achieve an app update without breaking anything
The bundle identifier for an app must always remain the same between updates, but the AppID can actually be different. So all you need to do is create a new AppID that used the same bundle identifier as the original app instead of a wild card.
Apps that use a wildcard still need a normal bundle identifier. The wildcard AppID lets you use any bundle identifier you like, but it still needs one.
There used to be an Apple article about this:
but it is no longer available online However, an archive is available.