Hi @ollipo,
Thank you for writing in, and sorry about that broken link, our new docs are still on work, we might have lost that link in the process. For now please follow this Step-by-Step Guide provided here, I know it says “Site to a New Host” but you can still follow that same process, except for the Step 7 (Defining New Domain & Search/Replace Old Domain), for the step 7 follow this process instead, Better Search Replace plugin is more reliable on migrating pages built in Cornerstone/Content Builder.
Remember to clear all your caching features (plugin, server-side, CDN, and browser’s cache) after migration. This will help you to avoid any potential errors.
Let us know how it goes,
Cheers!