How do i delete all indexes and change them to a monthly rotation?

My ELK installation is brand new and I want to remove all data that's currently in it and start with new indexes. But instead of there being an index for each day I want there to be a index for each week and that index to have 3 shards (I have 3 nodes in my cluster) and 1 replica of each shard. Can someone walk me thru this process? Ive been digging around and there is no clear process to making the changes I need. Thanks!!

I think I got it working. I reduced my shardes down to 3 + 1 replicas and I decided to just stay with daily rotations. Ill just close the shardes after 30 days and delete them after 90