Git login command line-login to github from command line with multiple accounts

I opened a new GitHub account to separate my biz vs. personal repository.

Now, I git init my local repo and git add remote origin 

I try to push and it seems to always take the credentials of my original account, not prompting me for the credentials for the new account.

I tried using the URL format with

https://:@github.com//

but that doesn't seem to help: I still get an error that the credentials are invalid for the original account username.

How do I log in with multiple sets of credentials or how would I somehow reset the original credentials to force password prompt when pushing? What should be the git login command?

EDIT:

The only way I managed to push right now is by specifying the username:password@github.com/ in the url in the git push command