Format an SD card, and place the update.zw file on to it. Put the card in to the Predator, and turn it on. The re-load should take about 30 seconds.
Really, you should have made a copy of the original firmware as a bin file before you modified your machine, but the above process should work. You may have to put both update.zw AND loader_zwif_SPI.bin on the SD card if the boot loader is not still in place on the machine.