Lots of jbl specialists are unsurprisingly in the USofA. Options I'm aware of:
repairs kits and bits can be found on eBay
somewhere like wilmslow audio may be able to help - http://www.wilmslow-audio.co.uk/
here's another place that google threw up; I don't know anything about them - http://www.speaker-repairs.co.uk/
Lots of jbl specialists are unsurprisingly in the USofA. Options I'm aware of:
repairs kits and bits can be found on eBay
somewhere like wilmslow audio may be able to help - http://www.wilmslow-audio.co.uk/
here's another place that google threw up; I don't know anything about them - http://www.speaker-repairs.co.uk/
Do you have the model number?