Migrating questions from postgres to bigquery source

I have a metabase instance where the data source is postgres. I have replicated the postgres database to bigquery and I want to re-create all of the metabase questions but use the bigquery data source. All of the column names/ tables etc are the same. All of the questions are created with the question builder there are no sql based questions. Is there a way to do this without manually re-creating all of the questions?

Not tried this, but what happens if you just edit the database connection (take a back up first!)