Sync with a fork - this assumes no merge conflicts.

sync_upstream.bat

@echo off

set OLDDIR=%CD%

cd /d %TEMP%

set /p repo=Enter the forked Git repo:
set /p upstream=Enter the upstream Git repo:

:: Clone the forked repo
if exist "forked_repo" del /q /s /f "forked_repo"
git clone %repo% "forked_repo"
cd "forked_repo"

:: Add the upstream remote
git remote add upstream %upstream%

:: Merge the upstream repo and push it up to the origin
git fetch upstream
git checkout master
git merge upstream/master
git push

cd /d %OLDDIR%