It's one of the functions returned from createBracket() Calling this method is almost identical to installing bracket (calling createBracket) into the same wrapper element.
import { createBracket } from 'bracketry'
const wrapper = document.querySelector('#your-wrapper-element')
const data = { ... }
const bracket = createBracket(data, wrapper)
bracket.replaceData(someNewData)
If you want to update individual matches (e.g., only some scores), replaceData will NOT be the best idea. Use applyMatchesUpdates instead.