how to remove the Spare wheel on my Hymer Tramp T676SL 2008

Hi I have decided to remove my spare when ,due to weight overload, Simple I thought !! Its the layout with 2 single beds at the rear, there is a about a 2" disc that you prise out in the Middle of the floor, looking down there is a round bar with with 2 pins sticking out, I couldn't find any tool to fit the bar so I made one & turned the bar ,which obviously unwound the cable attached to the centre of the round piece that supports the wheel . I turn the bar & the cable can be pulled down under the wheel but the wheel doesn't drop down . I can see some sort of mechanism that must release the wheel which would drop as the cable is wound down . but I can see no way of releasing this mechanism it is between the wheel & the floor.
I am wondering is there is a something missing from the factory tool kit that is used to release the mechanism allowing the wheel to drop. Can anyone advise me how to get the wheel out please thanks Bill