You need the Email Distribution Lists permission to edit a distribution list by changing its name, description, and/or updating the people included in the distribution list.
Click the Gear Icon in the Navigation Toolbar, and click the Email Distribution Lists link in the menu.
In the Mail Distribution List Browse screen, locate the distribution list you want to edit, and click it to select it.
In the Mail Distribution List screen, make any of the following edits:
Update the information in the Distribution List Name and Distribution List Description fields.
Click in the Distribution List People field to display the Address Book, and add/remove individuals from the distribution list.
Add an individual to the distribution list by clicking on their name.
Locate a person quickly by typing the first few letters of their first or last name in the Search field, and clicking . Click to clear the filter.
Remove an individual from the distribution list by clicking their icon in the Addresses list box.
Click Submit to close the Address Book. Ensure All People is selected in the list to the left of the Search field to include everyone in the Address Book (users, company contacts, and external people).