The best way to migrate between a traditional CMS and a headless CMS is by writing down all your content in a third party platform (we recommend Notion). From there, you can categorise, organise and ensure your content is perfectly aligned to structure your content. There's a great video about it here. However, we're going to break a trade secret. It's not an easy task. That being said the functionality of a headless CMS greatly outweighs the task of migrating most of the time. So don't be put off by the scale of the migration, just ensure you're picking the right headless CMS on the other side. *Cough* Sanity CMS