Elasticsearch update mapping for type within index and reindexing

Question

I've got an index called business_data which contains different types: Clients, Messages, Events etc... each one of these has its own mappings, analyzers, etc. I need to update the mapping for clients and reindex (reimport from activerecord, for example), without downtime. I've found a couple of articles online regarding zero downtime (create a new index, update the alias to direct to the new index, delete old index). These solutions discuss changing the entire index which means my entire business data... I only need to update the type. Is there a way to create a new type and simply change the alias? Any other suggestions on how to do it? Its a Ruby on rails app and I'm using elasticsearch-rails.

Thanks!