Thanks AussiePhil, will give it a tentative try, as I said it's been rounded a bit, just don't want to make a bigger mess of it. If it doesn't work I'll definitely look into a set of sae sockets or spanners FB or last resort take it to my mechanic to do it (old school guy whose worked on numerous mustangs plus other classic models so in good hands), just trying to become a little more self reliant with maintenance and repairs.