It's impossible for the soot to be coming from the actuator. The silver pot-like thing underneath is the vacuum chamber for controlling the variable vane mechanism. No exhaust gasses pass through it. I think the leakage you are seeing is coming from the particle filter which is the metal cannister to the left of the turbo (if standing in front of the car).
The likely reason it's leaking is that one of the clips holding the DPF together (either the one you can see in your photo to the extreme left hand side of the picture) or the one below which is basically underneath the car) has come loose. Tightening and/or replacing the clips as needed will fix the soot leakage.
I strongly advise against removing the internal turbo cartridge as the flow rate has to be calibrated precisely as do the stop points. Failing to do this and/or using substandard parts for the turbo internals can result in catastrophic failure of the compressor and possible engine or intercooler damage.
Besides, I don't think that the turbo is the problem if you are seeing soot, but rather the DPF filter. If it ain't broke....
In case you actually want to remove the plastic piping above the turbo (for whatever reason), it suffices to only remove one of the torx screws, if I recall correctly, it's the one to the right. The pipe then twists out using the torx on the left hand side as the pivot point.
To reiterate, in my opinion there is no need for you to rebuild the turbo and doing so won't help in this case.
Hope that helps!