Make a separate cylinder inside a group, oriented as desired.
It needs to be long enough to project completely through everything it needs to cut.
Locate it where desired.
Select the cylinder-group and the face that needs the hole.
Context-menu > Intersect with Selected
A line should now be cut where the cylinder-group intersected the face.
Move the cylinder-group away a fixed amount along an axis [type 1111mm]
Now you can see the cut.
Select and Delete the unwanted face[s].
If you want to keep part of the cylinder inside the newly cut hole then move it back 1111mm.
This time edit the cylinder-group and select-all, then Intersect with Model - this time the cylinder will have lines added where the other parts intersect it.
To see whats happening you can either Move it away again or use the simpler View > Component Edit > Hide Rest of Model toggle, so everything else is hidden...
Erase the unwanted parts of the cylinder, chances are that its curved surface will also be 'backwards' if merged into the rest of the model, so select it and context-menu Reverse.
Exit the edit and now you should have what's wanted...
Explode the group so it merges with the main geometry as desired...
Capture.PNG
