Ford C-max 1.5 diesel Fuel pipe re-connection

[Alan Scard]

I have managed to remove both fuel pipes on the top of the fuel filter and replaced the filter ok. I can replace the front pipe where you have to lift the white plastic ok. But I cannot seem to lock the rear pipe in place. This is the one where you have to press in the top and bottom white plastic when removing it. How do I get this pipe to lock in place? Any help would be appreciated.