Could anyone help please . Looked under bonnet this morning and saw radiator fan cover loose . Tried pushing it back on but wouldn’t stay . How should these be attached / why has it come off ? Your help would be appreciated as I have limited knowledge 😱😱

If you look at the second photo of eBay listing number 394480263963

you'll  see that there are three fasteners that are accessible from front side of the fan shroud.

Bit of a mission to get to them unfortunately, because it's tight to remove the fan shroud, after other fan is removed with its 'plastic tripod' bit.

Beware of rusty Tx30 fasteners that will round off if tool engagement is shallow. 

Bit hard to see from your pics, but is the fan motor part still attached to the shroud?

I don't think it's meant to be separable from the plastic blades, if that's what seems to have happened to yours?