If you're lucky there is a dust/pressure/scratch some sort of mark on the surface of the fretboard. Otherwise measure from the inside edge of the nut to the top of the 7th fret and double that from the inside edge of the nut to the inside edge of where the nut is a good place to put the bridge to start. Position may need a bit of tweaking from there...
updated by @ken-hulme: 01/02/24 10:34:56PM