what i do is pop mark the exhaust housing inline with the oil outlet hole with a center punch. slacken the bolts and remove the ones you can. then with a copper mallet and holding the turbo vertical by holding onto the comp housing, start tapping the exhaust housing off evenly away from the comp cover. just make sure you do it evenly or you might damage the turbine blades. and once you have it either off or slack just make sure you put it back in evenly too. final check is, is the turbo free to spin and not going to touch the casing even when pushing the blades to one side and spinning.