1. Open SQL Management Studio and the DB you need, then open the table PortalGroups for editing edit portal groups 
  2. Create the Group create portal group
    The list is probably empty now - so just create a new record and type in these things
    - MasterPortalID: The number of the portal which contains the users to share. In most cases this will be 1
    - PortalGroupName: Just any name you want
    - PortalGroupDescription: anything you want
    - AuthenticationDomain: your root domain
    - CreatedByUser: Add your host-user ID here, usually 1
    - CreatedOnDate: just add todays date
    - LastModifiedBy: use the same user as CreatedBy - probably 1
    - LastModifiedDate: also type in your ID, probably 1
  3. Assign the Portals which should be part of the group