When moving your messaging from product-centric to solutions-centric, you're going to bring in experts in the solutions you're trying to organize around. Whether that be industry, departmental or some other orientation, you will need the people who live and breathe these domains to ensure the messaging/content you develop resonates.
There can also be individuals that act as sales overlays or technical field resources to provide a level of domain expertise in customer conversations that will help in deals focused around these specific solutions.
Internal messaging to motivate the different stakeholders on why to "buy-in" or invest in this transition and communicating why it's valualbe to them is critical. These transitions can be hard and take time so ensuring the broader team knows why the company is going down the path (accelerate growth, expand market, etc.) is communicated is critical. Also, taking time to repeat this and constantly reinforce it is critical....not a one time communication but something that needs to be revisited often.