Edit a channel's title

1. In combined view select Channels, or on the left, select Teams  and choose any channel.

2. Select More options  () and choose  Rename channel.

3. Update the Channel name and Description (except General).
   Tip: Press Windows + . (period) to add an emoji to the title. 

4. Select Recommend that people show this channel in their channel lists if you'd like and then Save. 

While you can now rename the General channel, once changed, you can't name it back to General.