A few months ago, I was asked a similar question so I wrote instructions for this. It depends on whether the clusters are identical or not. The posts define what "identical" means.
If the source and target cluster are identical in configuration, follow the procedure here -- https://community.datastax.com/questions/4534/. If the source and target cluster have different configurations, follow the procedure here -- https://community.datastax.com/questions/4477/. Cheers!
