You just pull your BIOS chip out, install the BIOS Saviour in it's place, and plug your BIOS chip into the BIOS Saviour. There is a switch that allows you to choose between the primary BIOS chip, and the BIOS flashed into the BIOS Saviour. If you screw up a flash to the BIOS Saviour, just click the switch back over to your primary BIOS chip. The BIOS Saviour could then be flashed again.