Do you have access to a CAD software? (e.g. SolidWorks or SpaceClaim).
There, you can easily extrude, remove or simplify the undesired features in your geometry before importing the geometry to the Finite Element software (e.g. Abaqus or Ansys).
In case the geometry is not so complex, you could redraw the geometry directly on Abaqus.
thank you Ramio.. it is given model so it is difficult to modify in cad model.. (cause it is cae file) it is very small distortion. so i want to use abacus geometry tool (below ficture)