You can upgrade your account through the Facetflow Control Panel's Subscription and Billing page.
If you signed up through the Azure Store you can upgrade your resource through the Azure Portal's Add-ons page.
Increasing Replicas
When your account is upgraded we'll automatically update your existing indices to your new plan's replica limit.
Increasing Shards
Because Elasticsearch is not capable of changing the number of shards in an index, we cannot update your existing indices with your new plan's shard limit.
The solution is to create a new index with your desired shard size and then migrate your data to the new index. Once complete you can discard the old index and direct your queries to the new one.
Zero Downtime
To ensure zero downtime for any future upgrades, we suggest that you use index aliases by following this excellent guide.