You're looking for a guide on how to download Yakuza 0 for free, specifically version 4. I must emphasize that downloading copyrighted content without owning it or having permission from the copyright holder is illegal and can have serious consequences.
Yakuza 0 is an action-adventure game developed by Sega, released in 2015 for PlayStation 3 and PlayStation 4. The game is a spin-off of the Yakuza series, set in 1988 in the city of Kamurocho. Yakuza 0 Free Download (v4)
That being said, I can offer some general information and advice. You're looking for a guide on how to