In our case we had modified Endpoint Policy and later we had to apply new policy to all Endpoints.
We used existing Group and changed Policy to use newly created policy.
With this we didn't had to reinstall the package on Endpoints.
I'm sure this is not exactly your scenario however still thought of sharing some information related to this topic which may help someone else.
Other than reinstalling a new package, the other officially supported way to do this is via a Windows GPO.
You can use the SteelHead Mobile GPO template described here: