There are a few ways to force a distribution point to receive a new copy of a package (Application). However, the most effective way that I have found is to generate a new version of the package and force it to all distribution points. This way, if one of your DPs are being stubborn, it will see a new package and then receive it. If you are using the single instance storage model of Configuration Manager (default behavior), this won't generate a massive flood of data, as the necessary files will already be on the DP. They will only replicate to DPs that are hosting the package, but do not have ALL of the necessary files.
To do this, open the configuration manager console. Expend the Software Library tab and locate your application in the Applications node.
With the Application you want to replicate selected, click the Deployment Types tab. Right click on your deployment type and choose update content:
You will be prompted to confirm that you want to refresh the content. Select yes and a new revision of the application will be created. Make sure you understand this process, as it could deploy software to your clients!