as alex has said, it's going to be costly as you need to replace everything in the fuel system because it's been contaminated

so you start with the fuel tank, work your way along the fuel lines, filters, pimp, injectors, etc

our drivers have done it a few times, when we've had the bill back from ford/mercedes, it is always in the region of £3-4k

swap the filters, oil, blow through the lines with air to clean them up, flush everything through with clean diesel, then part chop it in for another jag