+ 1 on changing ALL gaskets while its off. Dont skimp on them, the last thing you want to do it change gaskets 6 months down the track after all this hard work.
remember to remove the water and oil lines BEFORE you try to take the turbo and manifold off. many people dont and bend the lines too much and they never go back. if you can stretch the budget, get a set of braided oil and water lines. well worth the money and trouble.
when removing the manifold. dont take each nut off one at a time. do them as per the service manual, there will be an order that you should remove the nuts in. this will stop the last nut from getting stuck.
if you find its pulling out the stud with the nut, just let it come out, youre not going to break it. you can put in a new stud.