How to fix an error when changing an account?

Question

git

I decided to change my github account. executed commands with new parameters
$ git config --global user.name "NewName"
$ ​​git config --global user.email "NewEmail"
when uploading files to the repository writes
$ git push -u origin master
Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.

Answer 1

need a new key
https://gist.github.com/jexchan/2351996