Elasticsearch 6.2.4 only keep data for 2 months

Elastic Stack Elasticsearch
1

I have setup the following:
[txt log files] -> Filebeat -> Logstash -> Elasticsearch -> Kibana

Now I want to have Elasticsearch to keep log data for two months.
How can I configure it?
I cant see any property for it in elasticsearch yml file.

(I have Red Hat Enterprise 6.9.)

2

Have a look at Curator project: https://www.elastic.co/guide/en/elasticsearch/client/curator/5.5/index.html

3

So I installed Curator.
Now how do I actually run a script?

I guess this is what I am looking for:
https://www.elastic.co/guide/en/elasticsearch/client/curator/5.5/ex_delete_indices.html