Battlestations: Pacific

Battlestations: Pacific

Kantai Kessen install help
I’m having trouble installing the Kantai Kessen mod. Whenever I open the installer application after extracting the files and it gets to the point where it’s installing the mod. The installer asks for me to insert disk 1 and then all other files in the game file folder get wiped, including the game itself. What do I need to do to avoid this?