To remove a remote, use git remote remove <name>
you can see more details by git help remote
Also, I believe changing the meaning of origin
is not a best practice, if you just need to temporarily push to a new remote, just add it with another name, such as: git remote add <name> <url>
When you add a new remote
you can see it with git remote
or git remote -v
to see url details.
Then using git push -u <your-new-remote>
would push your repo to <your-new-remote>
EDIT:
My fault, I didn't notice that git remote rm <name>
is also usable since it did not appear in git help remote