Introduction:
It's a small trick to create symlink using GF client instead of Steam's files.
Just for preventing Steam redownload large files everytime, and reduce the disk space usage.
Thanks to Lami Yui in SWHQ for suggestion.
1. Pause/stop steam's update if already in progress, then Fully exit Steam
2. Install GF client if you've not installed yet. Download
Now depends on different situation you are, follow few different steps: