Add or Remove Users from your SharePoint Group

To add a new member to your Sharepoint Group, login to Sharepoint and use the left pane to select the Team / Group you'd like to work from (you can also search for Groups / Teams in the Search Bar at the top).

After selecting your desired Group, click the cog wheel (Settings) in the top right corner of the screen.

In the Settings pane, click "Site Permissions"

Click "Add Members", click "Add Members to Group" and then type in the email(s) of the new group Members / Owners. You should see suggestions come up to choose from as you type

After your members have been selected, you'll need to use the drop down options to specify their level of permission (Member / Owner).

The individuals you specify will receive an email letting them know that they have gained access to the Group.