You have to update the class property: REST - /v1/schema | Weaviate - Vector Database
Oops, my bad. I always think you can do that, but you can’t.
Currently, this is the solution: Can I update the property of a class schema? - #2 by DudaNogueira
However, if you’re like me and have a copy of all of our data in a separate database, you could just delete the current class, create a new one with the necessary changes, then re-embed your data.
I have yet to try and migrate so don’t know how well that works.