Hotpont Mistral FF93N Fan and Blade set up?

I have just noticed a noise from the fan at the bottom rear right hand side of my "hotpoint mistral fridge frezer " model noFF93N when I looked the actual fan blade has come off and was split but mendable. Why it came off I do not Know. But has anyone out there got a Diagram or link to showing how the blade is mounted on the fan shaft and how it is secured and also how the actual fan is mounted and what you need to do to take it out. From what I can see a New Fan will cost me £75 which I really can't afford. Any Help would be Most Welcome. The freezer and fridge are holding temperature even though there is no fan blade on the fan motor which is comeing in when asked for. Roge