i always leave it hooked up... no need to take it off, it is barely being stressed. its no more of a no-no then using a pry bar to take the manifold off....

 

I just did this the other day to tighten my water bolts down... I was carefull and didnt need to take the oil feed line off.. But its probably best to do so. And yes the turbo to mani bolts obviously can be a biotch... I have 2 stock ones and 2 different ones... Previous owner had changed the turbo before to the 9 turbo thats on mine now.. So he was probably the culprit for this...