How to compress big files into small size ?

Guys ive seen 8 GB games compressed into 2 GB or 4 GB
please i really need to know that how to
thank
Answer #1
It’s a long process…
Usually involves:
-Ripping out unnecessary things (languages/intro’s etc…)
-Re-compressing the video/audio to save size
-compressing with kgb/paq8/uharc…