It took me a while to figure this out and I’m sharing my watershed moment with you.
When you create a github repo you can use HTTPS or SSH. You may not know why Github uses these two choices. There are probably a lot of technical reasons but a simple reason is one makes you have to enter in your github username/email and password (HTTPS) with each push and the other doesn’t (SSH).
So if you created your original github repo with HTTP and you want to change it to SSH this great article shows you how easy it is:
Essenitally, type this in your terminal and you’ll be off to the races:
$ git remote set-url origin firstname.lastname@example.org:USERNAME/OTHERREPOSITORY.git
The first time you’ll have to type your passphrase (if you created one when you set up your SSH key – instructions on how to do this)