Im trying to change the fuel filter on an M reg scort 1.8 diesel but the pipes have no primer on them. How do i fill the filter with fuel first? There is just two connections on top of the filter and a bolt on top of it. Can diesel be piped into the filter somehow to fill it up first, i dont want to get stuck with an empty filter and then struggle to get the car started.

Also while im at it, the cooling fan comes on straight away when the engine is turned on. Could a duff relay be causing this or is more likely it has been rewired to be on constantly. Car temp is fine, no overheating and plenty of hot air through the blowers. It cant be good for fueling if the fan starts straight up on a cold start.