How to reset BIOS blindly

I have an Acer 5745PG with hydro BIOS (I think that is what's it is called). It is version 1.1. i changed my bios setting to discrete instead of switchable graphics, but my graphics card crapped out and so did my standard vga driver so i am stuck with a blank screen. I need to change my bios back to switchable, but cant see to do it. I need VERY detailed instructions. i tried hitting f2 on start up followed by f9 to load default and f10 to save ans exit. it didn't work. Do i have to hit enter somewhere in there?