Once a Group is created, you can edit the name and update/change the permissions assigned to the Group by going Admin > Groups > clicking on the name of the Group that you want to edit.
You'll then click the "Edit" button in the top right corner to make your changes.
You can also add/remove permissions to and from Groups in bulk by going to Admin > Groups and selecting the checkboxes next to the Groups that you want to make changes to > Actions > and select one of the following options:
- Add Partner Resource - add Partner permissions to Partner Groups
- Add Distributor Resource - add Distributor permissions to Distributor Groups
- Add Internal Resource - add Internal permissions to Internal Groups
- Remove Partner Resource - remove Partner permissions from Partner Groups
- Remove Distributor Resource - remove Distributor permissions from Distributor Groups
- Remove Internal Resource - remove Internal permissions from Internal Groups
Learn more about Group permissions here: Group Permissions Defined.