How to modify a mapping?

hi

I can't seem to modify an existing mapping. Whenever I send the PUT command via curl, I'll get back an error saying merge failed. In this case I was trying to change the search analyzer.

{"error":"RemoteTransportException[[Gamora][inet[/10.32.139.142:9300]][indices/mapping/put]]; nested: MergeMappingException[Merge failed with failures {[mapper [tags] has different index_analyzer, mapper [tags] has different search_analyzer]}]; ","status":400}

I think I must be missing a trick somewhere. The only I've managed to change the mapping is to delete the whole mapping and recreate it all again.

Is there a way just to modify an existing mapping? anyone can help?

Thanks

D.