// drop the index
CFMetaData meta = CFMetaData.rename(cfs.metadata, cfs.metadata.cfName); // abusing rename to clone
ColumnDefinition cdOld = meta.getColumn_metadata().values().iterator().next();
ColumnDefinition cdNew = new ColumnDefinition(cdOld.name, cdOld.getValidator(), null, null);
meta.columnMetadata(Collections.singletonMap(cdOld.name, cdNew));
UpdateColumnFamily update = new UpdateColumnFamily(CFMetaData.convertToAvro(meta));
update.apply();
// check
assert cfs.getIndexedColumns().isEmpty();