Changing the manifold is not difficult. If you have a/c you will need to remove the bolts holding it in place and drop the belt off so you can access the front bolts. Turbo heat shield will also need to come off. I recommend that you soak all the mainfold studs and nuts twice a day for a week before removing them otherwise you could snap one.
Other than that just make sure you get a new manifold gasket as well as one for the turbo joint
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