To install the AetherSX2 APK and BIOS on your Android device, start by downloading the latest AetherSX2 APK file from the official website or a trusted source. Once downloaded, go to your device settings, enable "Install from Unknown Sources," and install the APK. After installation, you'll need a PlayStation 2 BIOS file to run games—this must be legally obtained from your own PS2 console, as distributing or downloading it online is illegal. Place the BIOS file (usually in .bin format) into a dedicated folder on your device. Open AetherSX2, navigate to the BIOS settings, and select the BIOS file.