Remove center caps on dynamique wheels?

[Alex5]

Sorry to be such a noob but to remove the centre caps to get to the bolts there is a strange nut thing and I have no idea how to open it, do I need a special tool or something?

 

[Dan@M.A.D]

Bullnose pliers work perfect, There is a tool that should come with your car but most people loose it..

 

[Alex5]

Wicked found the tool was tucked away in the car