After a group has been created you can modify the functions available to group members and manage group membership.
To modify group setting you need to log on to Blackboard and open your course, in Control Panel, click on Groups under Users and Groups.
In the Groups page, find the group that you want to modify and click on Edit from the action bar.
Change the Group Name and Description if you want.
In the Tool Availability section, you can set what functions the students will have in that group. These functions will only be available to the students within the group. The functions include Discussion Board, File Exchange, Group E-mail Function, and so on.
As with most item in Blackboard you also have to select if the item will be visible.
Select Allow Personalization, if you allow students to personalize group space modules.
Now you can select the members for the group by moving users from Items to Select field to Selected Items field. You can also remove users from the group by moving users from Selected Items field to Items to Select field.
Click on the Submit button to finish the process.