Delete index pattern names

[Timshs]

I have a problem generating to heavy a log system.
Now our current Kibana shows 15067 fields in my logstash-* index pattern. This should not be this much.

How do I delete names I do not want to index ?
I think I must correct the mappings for my index right ?
And how do I do the above without having to loose old logs data and keep using my dashboard and visualisation ?

I know that I can tell it to be more stricst in elasticsearch.yml with new name fields by adding this line:
action.auto_create_index: +field value, +another field value*

Hope you can give me some pointers

[Marius_Dragomir]

You could use the source filters in Kibana to limit the number of fields that you want to get from ES.
Go to Management -> Index Patterns -> Source filters and you can add fields there that you want excluded.