Managed to remove it. But will list how its done if anyone needs to know
1. Remove the fan protective plate. You will need a star shaped tool. If like me you the screws had rusted and carnt undo them you can ently know them through from the back. Then you will need bigger self tapping screws to replace them.
2. Once you have undone the fan nut you will have to remove the black washer. Then with a vice grip hold the fan motor shaftand spin the fan and wriggle it and it will come lose.
A word of advice try and get a neff replacement part rather tahn a universial part. I got the part cheaply from 1STCALLAPPLIANCE however the orginal is only a fiver more. The issue with the universial part was the electrical termainals had to be twisted and bent as they were to big to fit through the hole in the back of the oven
kieran
August 2007