git remote add origin <repo>
git push -u origin master # pushes up the repo and its refs for the first time
Changing URL between SSH and HTML can use git remote set-url
too.
git remote set-url <remote name> <repo>
# remote name can be origin or upstream in common.
git remote -v # list existing remote names
# set
git config --global http.proxy http://<username>:<password>@<proxy server>:<proxy port>
git config --global https.proxy https://<username>:<password>@<proxy server>:<proxy port>
#unset
git config --global --unset http.proxy
git config --global --unset https.proxy