Login to http://mail.office365.com with a user account who is an owner or administrator of a group

2. Access the website - https://outlook.office365.com/ecp/

3. In the Options page, click on groups.

4. The Groups page shows the Groups the user is a member of and the groups they are owners of

5. In the "groups I own", double click the group you want to manage or select the group and click the pencil to edit the group

6. In the group details window, select membership

7. The members of the group will be displayed - to remove a member from the group, select the user and click –

8. To add users, click +

9. In the address book list, select the users you want to add to the group by clicking on the + next to the user 10. When all the users have been selected, click Ok

11. Back on the group details page, click save