how to use createReadStream instead of readFileSync

[at4446]

I was wondering how it is possible to use createReadStream instead of readFileSync? I am trying to read an xml which is 500MB so node is running out of heap memory so I need to read the file in chunk instead.
let json = convert.xml2js( fs.readFileSync(entities.xml), { instructionHasAttributes: true, compact: true, spaces: 4, reversible: true, } );

when I change fs readFileSync to fs.createReadStream I get the following error:

UnhandledPromiseRejectionWarning: Error: Text data outside of root node.