There are two buttons on the groupings menu that does basically the same thing. They both will list all the groupings you have created and allow you to click on the grouping row to start or stop each one. You can also edit, add to or delete each grouping with buttons.
You can edit any groupings by pushing the edit button. It will pull up a dialog window showing all the jobs in the groupings. At the top you can edit the grouping name or description by clicking on the text. If you want to remove a job from the grouping just click on it and it will turn red. Clicking it again it will turn green and won't be removed. Right click on a job to make it go in a Delayed Ham mode when grouping is on and it will turn a dark green color for the background. Once you are satisfied you can save it and that's it.