After filling his diesel car up with petrol, my mates car has been diagnosed with faulty injectors, and a number of garages say they could do the work but are talking loads of money.

I have never worked on a diesel Jag, but am handy at twirling spanners and have changes injectors on other cars. I havent had a chance to look under the bonnet, but before I commit myself to a 120 mile round trip, how difficult is it to get at and change the the injectors on a 2005 X-Type 2.0 diesel Jag?