Go here, download the zip file you need. See where it says all regions? Click to download that zip file. If you ahve V1, get the V1 version, if you have the V2 get the V2 version obviously.
So now you have the zip file downloaded. Extract it so you have the 2 files ready to transfer.
Now connect your fuze to your computer. You should still be able to open it. If you dont care for your music at this point delete all the folders and files inside it. Now take the 2 files (clpp_data, and fuzpa) and transfer them over to your fuze hard disk.
Unplug the player after the transfer is done. At this point turn off the fuze player by holding the power button in the up position for 20 some seconds. Now hold LEFT on the wheel and power on the player. It should start loading the original firmware.