EWS operation to edit Distribution list - exchangewebservices

Question

I am looking for an EWS operation to edit a Distribution list. Here edit means, adding\deleting a existing contact into\from an existing group or changing Display Name of Group.
I have tried option like mentioned in following link:- https://social.msdn.microsoft.com/Forums/office/en-US/db110c4e-a0f2-40de-9276-3e30458b254f/ews-maximum-number-of-members-in-a-contact-group?forum=exchangesvrdevelopment
Also used properties like AppendToItemField, SetItemField and DeleteItemField?But error comes as "The method or operation is not implemented"

Answer 1

Finally i got the answer for Editing Groups. here is SOAP call which worked for me:-
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
<soap:Header>
<RequestServerVersion Version="Exchange2013" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" />
</soap:Header>
<soap:Body>
<UpdateItem ConflictResolution="AutoResolve" MessageDisposition="SaveOnly" SendMeetingInvitationsOrCancellations="SendToNone" xmlns="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
<ItemChanges>
<t:ItemChange>
<t:ItemId Id="AAMkADZmMjJlMDk...." ChangeKey="EgAAAB..." />
<t:Updates>
<t:AppendToItemField>
<t:FieldURI FieldURI="distributionlist:Members" />
<t:DistributionList>
<t:Members>
<t:Member>
<t:Mailbox>
<t:ItemId Id="AAMkADZmMjJ..." ChangeKey="EQAAABYA..." />
</t:Mailbox>
</t:Member>
<t:Member>
<t:Mailbox>
<t:EmailAddress>user#contonso.com</t:EmailAddress>
</t:Mailbox>
</t:Member>
</t:Members>
</t:DistributionList>
</t:AppendToItemField>
</t:Updates>
</t:ItemChange>
</ItemChanges>
</UpdateItem>
</soap:Body>
</soap:Envelope>