Currently, an in system Sample editor is not available. If you need to edit your Sample attributes by adding, modifying or removing columns or updating values, you will need to export a CSV file of the Samples from a SampleSet, modify the columns and/or their values, then re-import the Samples CSV using the Samples Importer App. This will not modify existing data or analysis that has already been run. To update the analysis results, you will need to re-run the analysis apps using the new SampleSet with your recently updated Samples.
Similarly, subsets and supersets are under development. Currently, the most efficient way manage subsets of samples is to upload separate SampleSets for each subset, and a complete SampleSet to represent the parent set. In the same way, a superset can be created by downloading SampleSets, combining them, and then uploading the combined set.