I believe you have to take the turbo off. Underneath the engine, take the belly pan off, looking up from the bottom, feet at the front, its on the right at the back of the engine.
Mike

be careful starting the engine up with a turbo that you suspect has gone because if it has it can run on the engine oil and then you engine will go too before you can stop it and the only way of stopping it is to shut off any air into the engine like stuffing a plastic back up the intake pipe

So given that it is smoking so badly, can anyone give me some tips as to how to move forward with a diagnosis. We cannot really afford to take it to the garage and to be honest it cannot be driven as the amount of smoke is something else when you try and drive it.

Just for my own understanding. If the turbo seals have been blown, then I can expect to find oil in the air inlet manifold. There was plenty in there before I replaced the crankcase breather anyhow. I had to put the air inlet manifold box over a container to catch the oil.

Thinking about what I have just written, it would seem turbo seals are the issue?

Would the engine rev roughly if your turbo was hosed and you were introducing oil into the air inlet manifold?

Thanks