def rm_eltorito(self):
        # type: () -> None
        '''
        Remove the El Torito boot record (and Boot Catalog) from the ISO.

        Parameters:
         None.
        Returns:
         Nothing.
        '''
        if not self._initialized:
            raise pycdlibexception.PyCdlibInvalidInput('This object is not yet initialized; call either open() or new() to create an ISO')

        if self.eltorito_boot_catalog is None:
            raise pycdlibexception.PyCdlibInvalidInput('This ISO does not have an El Torito Boot Record')

        for brindex, br in enumerate(self.brs):
            if br.boot_system_identifier == b'EL TORITO SPECIFICATION'.ljust(32, b'\x00'):
                eltorito_index = brindex
                break
        else:
            # There was a boot catalog, but no corresponding boot record.  This
            # should never happen.
            raise pycdlibexception.PyCdlibInternalError('El Torito boot catalog found with no corresponding boot record')

        del self.brs[eltorito_index]

        num_bytes_to_remove = 0

        # On a UDF ISO, removing the Boot Record doesn't actually decrease
        # the size, since there are a bunch of gaps at the beginning.
        if not self._has_udf:
            num_bytes_to_remove += self.pvd.logical_block_size()

        # Remove all of the DirectoryRecord/UDFFileEntries associated with
        # the Boot Catalog
        for rec in self.eltorito_boot_catalog.dirrecords:
            if isinstance(rec, dr.DirectoryRecord):
                num_bytes_to_remove += self._rm_dr_link(rec)
            elif isinstance(rec, udfmod.UDFFileEntry):
                num_bytes_to_remove += self._rm_udf_link(rec)
            else:
                # This should never happen
                raise pycdlibexception.PyCdlibInternalError('Saw an El Torito record that was neither ISO nor UDF')

        # Remove the linkage from the El Torito Entries to the inodes
        entries_to_remove = [self.eltorito_boot_catalog.initial_entry]
        for sec in self.eltorito_boot_catalog.sections:
            for entry in sec.section_entries:
                entries_to_remove.append(entry)

        for entry in entries_to_remove:
            if entry.inode is not None:
                new_list = []
                for linkrec in entry.inode.linked_records:
                    if id(linkrec) != id(entry):
                        new_list.append(linkrec)
                entry.inode.linked_records = new_list

        num_bytes_to_remove += len(self.eltorito_boot_catalog.record())

        self.eltorito_boot_catalog = None

        self._finish_remove(num_bytes_to_remove, True)
Remove the El Torito boot record (and Boot Catalog) from the ISO.

        Parameters:
         None.
        Returns:
         Nothing.