How to edit a mphbin file?

Hi all,

Is it possible to open and edit a geometry import file in Comsol? For example:

www.comsol.com/model/microwave-heating-of-a-cancer-tumor-30


At the Above application, there is a mphbin file which consists a rectangular geometry, I would like to convert it a circular geometry. How can I achieve this?

Thanks in advance.