I guess some directions are a bit tough to follow.Do you have the wiisx folder on the root of your SD card? The WiiSX folder will contain 3 more folders, bios, isos, saves. The bios file you downloaded goes in the bios folder (bios is needed), the ISO goes in the isos folder. That's all there is to it.
I wonder if he is using the newest version of the emulator, didn't the older version have the bios in with the game ISO's?