To extract information of all communication channels from PI system into an excel.
1. extract port first from client proxy (CommunicationChannelIn use this WSDL , it will be easy for coding as there is no need of using object factory).
2.call query function( by passing required channel name or part of channel as Query request ) and fetch communicationchannelID from query response.
3. Send same CommunicationChannelID(PartyID ,ComponentID and ChannelID) as Read Request and you will get CommunicationChannel details as Read response. Write same details to XL sheet.
Use the same excel to update the channels in PI
1. read details from XL sheet to a list ,of type CommunicationChannel.
2. Change same details to CommunicationChannelRestricted , so that you can change communication details.
3. get port details for proxy and call change function and pass CommunicationChannelRestricted as parameter.
Note: You need to create Changelist before changing channel . if don't create a changeList for each changed channel we will have individual changelist will be created in ID.
Change communication channel names using this excel to confirm to correct naming standards.
Changing communication channel name will not be supported by Directory API and not even but ID. But, you can create number channel using the same.
Let me know, if you stuck some where 
Regards
Hari.