You don't exactly edit a channel, you upload a new package. You should be able to see the channels you created on the developer dashboard:
If you lost the login credentials then you'll have to contact Partner Success. Good luck with that.
If this was a Direct Publisher channel then I have no experience with them.
Did you create this channel in the first place? Whomever did had to upload a package which is basically an encrypted zip you create on a Roku device.
I did make one I just have never heard the term package can you explain what that means I know I have to go in and resubmit everything is that what your talking about. sorry if I dont get all the terms
@savair You should clarify how you made the channel. Did you use the SDK, or, Direct Publisher? Your answer will determine how you proceed next.