Don't do it this way unless you have a mk3.

if you have a mk4, then open the image of the v31/v32 (using ultraiso or magiciso etc) and then drag and drop the navboot to the same dir that you have navtweak, then do the edits and save (as navboot), then drag and drop the new navboot back into the open v32 image (using ultraiso or magiciso etc) and then save as a new image (eg v31_mine.iso), the use imgburn to burn the new image to disc, remember to use the slowest rated speed of the disc or x1 speed.

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Sept 03, M3, Silver Grey. Retro-fits: Modded Mk4 DVD Drive, OEM Bluetooth, VR Control, Rainbow Speaker Upgrade, Sony SOT Amp, HK Sub, CCFL, Intravee II, NightMode.