There are 3 ways to flash the BIOS on an EPoX motherboard, using Magic Flash from Windows(not an option for you), ALT+F2(might be an option), or Boot Disk(not an option). I have to admit I think the AT+F2 should work without a processor installed, but I am not 100% sure, however it is the only option you have unless you happen to have an old processor lying around.
Here is how it works:
The ALT+F2 Method
1. Download the required BIOS image file from the EPoX website.
2. Copy or extract the BIOS image file (named xxxxxxxx.bin) to a blank
floppy disk with no bad sectors on it.
3. Restart the machine with the floppy disk in the floppy drive
When prompted at machine initialization, press ALT+F2 to begin
performing the flashing of the BIOS.
4. The BIOS will automatically flash and reboot the machine.
5. After this, press DEL to enter the BIOS setup and select to "LOAD
OPTIMIZED DEFAULTS". After doing this select to "SAVE & EXIT."
6. Please note that this does not create a backup of the BIOS binary file.
7. This does not require you to have a bootable floppy disk.
That's it, it's worth a shot...good luck