[phenixbb] pdbtools: how to set the occupancy for an atom selection?

Hello, I was wondering if someone could show me a way to set the occupancy of a specific set of atoms to 0 using phenix.pdbtools. I noticed here http://www.phenix-online.org/download/documentation/cci_apps/pdbtools.html#a... that there is no option under modify => occupancies to do an 'atom_selection'. Any help would be appreciated. Cheers, Alex