Beat the Leftists to it -- Replace the Constitution now (with suggestions).

Leftists in Chile getting their constitution replaced. It can happen here.

Answer, though, is for Right to head off the Left and create new governing system in current setting that ices out Left.

https://www.batimes.com.ar/news/latin-america/chileans-overwhelmingly-vote-to-scrap-pinochet-era-constitution.phtml

To get the process started: