Another way would be to add the original repo, to be copied, as remote for our current repo.
#create a new repo in the org1 organization called myrepo-new
In your local terminal, run:
git clone git@github.com:org1/myrepo-new
cd myrepo-new
git remote -v #shows current repo link on github as origin
git remote add name-for-remote https://github.com/org1/repo-old
git remote -v #shows repo-old as name-for-remote
git fetch name-for-remote
git merge name-for-remote/branch-to-get-from-remote
#Now fix any conflicts if present
#If number of files/commits is very high, the desktop client may hang when you try to commit your changes after merge. Try switching to Git Shell if this happens.
git status
git commit -m "commit message"
git push origin master