How to clean the venturi pipe sensor holes. D13 engine

Hello guys.
I have this 2010 780 with D13 engine. I have a bunch of issues with lack of power and a lot of soot in the oil.
I replaced a bunch of stuf, including the EGR valve and EGR differential pressure sensor and made no difference.
I tried to clean the holes in the venturi tube, that are used by the DP sensor to measure the difference in presaure, but i couldn't find the direction the holes go from the sensor port to the flow tube.
I understand are some narrow channels that get clogged with soot.
This is the updated plastic venturi tube.
How do you guys clean those?

Any tips?

Thank you very much.