[vtkusers] Removing a cell from a cell

[jarv0075]

This one seems like it should also be very straightforward but searching
the archives hasn't produced anything yet...

The question is, how do I remove the area of one cell, from the area of
another?  I.e., I can't just 'delete' the cell which is the filled in hole,
because the underlying region (the area which contains the hole' is
generated with the hole automatically filled in.

Everything I've searched for (using any number of terms) has come up with
using a plane/sphere/etc to clip my data, which in this case isn't going to
work.  I'm sure there's a nice easy way to do it, but it's a case of how do
I find it if I don't know what I'm looking for?

Thank you again