Index_already_exists_exception while updating analyzer setting of existing index

[Mahesh_Lawand]

I am trying to update analyzer of existing index.
For that i have followed following steps -
1.Close index
curl -X POST "http://server/index_name/_close"

2. Update setting:
   curl -XPUT 'http://server/index_name' -d '{
   "settings" : {
   "analysis": {
   "analyzer": {
   "danish": {
   "type": "danish"
   }
   }
   }
   }
   }'

But its throwing error
{"error":{"root_cause":[{"type":"index_already_exists_exception","reason":"already exists","index":"index_name"}],"type":"index_already_exists_exception","reason":"already exists","index":"index_name"},"status":400}

How to update analyzer setting of existing index?