How do you change a nation's flag?

Fiji's prime minister Voreqe Bainimarama wants to change his nation's flag. He calls the current flag - featuring a blue ensign with the British Union Jack in the top left hand corner and a shield with the cross of St George and a lion - 'outdated'. Mr Bainimarama wants a new design that puts Fiji's colonial past firmly behind it. So how do you go about changing your nation's flag? The BBC's Jon Bithrey asked British vexillologist - or flag boffin - Graham Bartram how common the existing design is. #flags, #Fiji, #Bainimarama, #vexillologist