Moving a site in the same domain

I have two sites on the same domain. Submrge.org is an old site, submrge.org/testing is a new site I’d like to switch over to.
Both have their own databases and they don’t share media.
Can I accomplish the switch just by changing the urls in the Settings/General options? Should I change the urls in the submrge.org settings or the submrge.org/testing settings?
Thanks!