Fuel system

Hello I need some help I have a clio 1.5dci dynamique s 2005. I took the car to renualt and they have found metal in the fuel they have quoted me £4500 to fix this issue. A friends of mine has said I can buy secondhand parts and do it my self. I can do everything appart from removing the fuel tank does anyone know if you have to remove the axel. Also how can I flush the metal out of the fuel pipes I need help!

Thanks