Starting help needed

[TheDarkSide]

Evening all!

Just returned from a 700 mile jaunt across lakes and dales and, as could probably have been predicted, the Cerb's given me a couple of jobs to attend to on our return home

Somehow the starter's permanently being activated; fortunately the RAC man managed to bypass the trigger wire to get us home but now I've got a fubar starter motor and an unknown electrical fault, so (and this is where the knowledge of the Cerb fraternity is required)...

1, is there an idiot's guide to changing a starter on a 4.2 anywhere? I've looked on the online workshop manual but can't find any reference there. Do the fuel rail and inlet pipes have to come off and, if so, is it a job for a slightly inept DIYer like me?

2, any clues as to what might be permanently triggering the starter? Is it likely the black switch is faulty? Is the starter function controlled by a little black box somewhere or is it just a case of having to do wiring checks?

Thanks in advance for your help folks, I'm off to unpack and push the car into the garage

[HRG.]

If you need a man with a multimeter who knows how to use it gimme a shout