LOL! Sounds fun!!
Doesn't sound that bad to be honest, as long as the pin is easily removed, the drilling of the aluminium compressor housing should be fairly straight forward though critical attention and care would be needed.
I assume in this case that to remove the compressor housing, you'd best be pulling it straight off towards you to make sure that you lose the pin...
But yeah, I genuinely don't think I can remove the turbo and exhaust manifold assembly out from either the top or bottom (damn torsion bar!), this would mean getting those nasty looking nuts off that attach the turbine housing to the manifold. Can't even get a socket on those!!
I do however have a plan which may not involve clocking the turbo at all...
I've ordered some 90 degree 1.75"-2" silicone reducer hoses and intend on making up a straight-out but very short intake stub, it looks tight but going off rough measurements, the flexibility of the hoses should allow for enough wiggle room. Though it may mean trimming them down and I'm certain they would touch but we'll see how it goes!
So I have a 2D design for the flange plate required but my friend in the sheet metal factory has gone AWOL this week.
This design is to the spec of the original intake stub and my idea is to get a 1.75" pipe welded to it maybe only 1"-1.5" long, depending on the thickness of the pipe I go for there will likely be some overhang form the plate's centre hole, but I'll just fill it smooth with some epoxy putty/resin so it doesn't mess with the air flow.