To begin with, everyone (reporters, sub-editors, editors, photographers/videographers, design/layout team, etc.) would be brought on board to agree that solutions journalism is a good investment of their time and efforts.
Next, they'd need training.
After that, a strategy would have to be designed, and actionable, measurable outcomes fixed: Who files a solutions story, how often, e.g. Whether it gets play on the front page or in the weekly newsletter. If an infographic can be used to promote the story on social media. And so on.
Reporters and sub-editors would need support for the first few stories (and on an ongoing basis).
Periodically, the approach would need to be reviewed to see how it's landing with audiences, whether it's proving feasible for the reporting and editing teams, and so on.