In the meantime, ID change will be available in beta form through the PlayStation Preview Program. However, only users who've registered for previous system software betas will be eligible. The testing phase is slated to wrap up in November.
However, the announcement warned that changing IDs will cause some compatibility issues with games that launched before April 1, 2018. To fix any problems that arise, Sony will allow users to change back and forth between their original and new ID at any time.
Moreover, there will be an option available to users when changing a PSN ID that will let them display the old ID next to their new one for easy recognition purposes. However, unlike the previous setting, this option is only available while applying the change and not after.
Once the feature comes out of beta, changing the Online ID for the first time will be completely free of charge. Subsequent changes will cost regular users $9.99 every time, but PlayStation Plus members will only need to pay $4.99.