Removel of Sram Hub Gear Thingy

[LordoftheTeapot]

Can some one please help me? I need to remove the gear control 'case' so I can then get at the locking nut to remove rear wheel. How do I take the Sram casing off?
(Please see photograph)

 

[LordoftheTeapot]

It's OK, went to the web-site and viewed instructions