The stock BIOS can be installed directly from within Windows and also has a DOS installer as well, but I am not sure about the unlocked BIOS. Here is a screenshot of the files within the zip file for the unlocked BIOS:

The BIOS itself can be found for download here:
https://dl.dropbox.com/u/24459764/Acer_Aspire_V3-771G_Unlocked.zip
There are no instructions in the zip archive, which I think is just stupid!
Can anyone give me an idea of how to do this, because I assume there are people here who have installed unlocked BIOS in their PCs before?