The turbo itself will be the least of your problems. Just installing a new turbo will not be enough. This is a known problem of the older 1.6 TDCI engine. Usually the turbo fails as a result of the lack of engine oil. Because the small sump the engine oil becomes dirty quite quickly. The dirty oil cloggs the oil line which runs to the turbo which causes the turbo to break down. A shortened oil change interval is recommended on this type of engine.
To solve this problem you have to perform a procedure recommended by Ford and many turbo specialist. If I remember correctly this is the following procedure:
* Perform an engine flush.
* Drain the engine oil and change the oil filter.
* Remove the sump to clean it.
* Change (or remove) the strainers of the oil line to the turbo.
* Change the turbo.
* Fill the engine oil.
* Start the engine and warm up the engine (idling).
* Measure the amount of oil running to the turbo.
* Change the engine oil and filter.
If the amount of oil running to the turbo is within specifications you should be fine. If the amount is too low the engine is probably already slightly damaged. In this case changing the engine or a complete engine rebuild may be necessary.