You can delete an app layer or layer version, as long as it is not being used by another layer as a prerequisite, or deployed to an image template. Deleting the layer itself removes all versions and resources associated with the layer.
In the Management Console, select Layers > Application Layers.
Select a Layer to delete.
Select Delete Versions in the Action bar. This opens the Delete Version Layer wizard.
In the Version Selection tab, select the Version you want to delete, or select the Delete Layer check box to delete the entire Layer and all Versions.
In the Confirm and Complete tab, verify that the correct Version (or Layer) is selected for deletion, enter a comment if needed, and click Delete Versions.(missing or bad snippet).