Citroen ZX 1.9D Lucas Fuel Pump?

I have a Citroen ZX 1.9D with a leaking Lucas Fuel pump. I don't want to spend £80+ for a mechanic to replace the 'O' rings which cost me £3. That said, is it a job which can be attempted myself? No, I'm not a mechanic, but could follow instructions and a diagram IF ONLY THEY WERE THERE ON THE NET!!!

Many thanks ..... in hope.