You can add release content and remove it from release trains from the release train view. In the default implementation of Serena Release Manager, associations to release trains can be done only when the release train is in the Planning state.
To associate release content with a release train:
Navigate to a release train and select the Release content tab.
Click Add release content.
Select a process app from which to choose a report.
Select a report from which to choose content.
Select content items to associate with your release train.
Click OK.