Add users to a group
You can add users to a group at any time.
On your website or team site, click Share
If you see Members instead of Share, click Members, and then click Add members.
By default, the Share dialog that appears displays the message Invite people to Edit or Invite people. This invites the users who you add to join the SharePoint Members group. To choose a different group and permission level, click Show options and then choose a different SharePoint group or permission level under Select a group or permission level.
In the Enter names, email addresses, or Everyone box, enter the name or email address of the user or group that you want to add. When the name appears in a confirmation box below your entry, select the name to add it to the text box.
If you want to add more names, repeat these steps.
(Optional) Enter a personalized message to send to the new users in Include a personal message with this invitation.
Click Share.
Remove users from a group
On your website or team site, click Settings , and click Site settings. If you don't see Site settings, click Site information, and then click View all site settings. On some pages, you may need to click Site contents, then click Site settings.
On the Site Settings page, under Users and Permissions, click People and Groups.
On the People and Groups page, in the Quick Launch, click the name of the group that you want to remove users from.
Select the check boxes next to the users who you want to remove, click Actions, and then click Remove Users from Group.
In the confirmation window, click OK.