This part really can't be over stated... ... . be prepared to have your hands full when you go to separate the housing from the turbo.
LOTS of PB or whatever you prefer is needed... and often some very serious "Wailing" on the exhaust end is needed to get it to pop off.
If you need to resort to violence with a small sledge then you need to wack it hard at 12:00 and 6:00, then, reach in and see if the pinwheel still turns without touching or rubbing noises, if it does wail on it at 9:00 and 3:00, repeat pinwheel spinning to make sure you are not binding.
You'll need someone to hold the drive end/side of the turbo while you inflict the violence and rotate the turbo.
It can be a bit tricky since binding can damage the pinwheel so be careful and take your time. .
You can try using the the 4 bolts that hold the exhaust side on, as kind of wedges or threaded levers to push the hot end off. You will need to put a "spacer" of some sort between the bolt heads and the compressor side for the bolts to "push on".
Between those things, you should be able to get it off. .
When you do get it off, take care not to bang or damage the pinwheel, and clean the mounting groove well, then apply anti-sieze to the groove, the bolts and the manifold/turbo bolts too.
This will help you if you ever need to remove it again.
Make sure when you put it back together, that the oil inlet and outlet are as verticle as possible so you get good supply/drain from the turbo.
Good luck... .
Bob.