This is the holy grail of FIFA modding. The Mod Manager is the tool that acts as a bridge between the patch files and your game directory. Without this, you cannot install patches.
To successfully install the Classic Patch for FIFA 16, enabling retro teams, classic players, historical kits, and legacy stadiums without corrupting the base game or causing crashes. fifa 16 classic patch install
The installed successfully following the described manual method with BH regeneration. The patch delivers a rich retro experience (e.g., 1998 World Cup, 2000s Champions League teams) but requires strict adherence to the regeneration step and a clean base game. Recommended for offline single-player and tournament modes only. This is the holy grail of FIFA modding