Derefining Mesh

Hi all,

I have a large multi-layer version 6.2 model with fine discretisation in the mesh around proposed abstraction bores.  I would like to move the bores and "derefine" the mesh where the bores were previously located to speed up the model.  However when I select an area either in element or nodal modes, I cannot get the derefinement to work.
Does anyone have any suggestions as to how to derefine the mesh?
regards
Anthony

The derefinement only works on parts of the mesh that have been refined before. If the mesh has been created in a fine way originally, there's currently no way to coarsen it in a certain area.