There is no native to Nutanix method of converting an existing File Server in a customer infrastructure into a Nutanix Files server. The reasons are numerous and once you dive a little into the architecture of Nutanix Files they become apparent.
There is however a method of migrating existing data from a file server to Nutanix Files using third party tools like Robocopy, DatadobiMigrate and Peer Software to name a few.
At Nutanix we strive to make experience of using the platform as easy as possible hence we created Nutanix Files: SMB Migration Guide. This guide provides an overview of best practices and considerations when migrating from third-party platforms to Nutanix Files when using the SMB protocol. We also walk through an example of how to perform a migration.
For more information please see Solutions Documentation section on the Nutanix portal. Note that you can filter the list by Solution Type at the top right corner.
For exhaustive guide on Nutanix File please see Nutanix Files Guide.