seLain

ref stackoverflow:
https://stackoverflow.com/questions/41283955/github-keeps-saying-this-branch-is-x-commits-ahead-y-commits-behind

works by
1. git remote add upstream https://github/upstream/repo.git
2. git pull --rebase upstream master
2.1 git rebase --skip  (if the conflicts are not true, skip the patches)
3. git push --force-with-lease origin master

If there are branches to fix

seLain

git fetch --all  # or whatever to make sure your repo consistent with origin
git checkout -b new_branch_for_single_change upstream/master # or origin mater, dependes where's your base source
git cherry-pick hashcode_of_specific_commit
git push -u origin new_branch_for_single_change  # push this new branch to origin

then create PR from new_branch_for_single_change branch on origin to upsteam

seLain

https://help.github.com/articles/checking-out-pull-requests-locally/

checkout from origin

git fetch origin pull/ID/head:BRANCHNAME
git checkout BRANCHNAME
<do modifications>
<add>
<commit>
git push origin BRANCHNAME

seLain

https://stackoverflow.com/questions/3042437/how-to-change-the-commit-author-for-one-specific-commit

git rebase -i <earliercommit>
for each commit you want to change:
    change the text from "pick" to "edit"
    git commit --amend --author="Author Name <[email protected]>"
    git rebase --continue
git rebase --continue

done