Place the file in the Documents/PCSX2/bios directory.
Move these files to the bios folder of your emulator. Using the BIOS with PCSX2 Ps2 Bios Japan Scph-90000 Download
Open PCSX2, go to Config > Plugin/BIOS Selector , and click the BIOS tab. Refresh the list and select the Japanese v2.30 entry. Place the file in the Documents/PCSX2/bios directory