Converting custom collection to blog

Hello!

I inherited a site that uses a custom collection type, a blog that is user-orderable. Is there a way to convert it into a generic blog?

For context, I'm looking to safely disable Developer Mode and change themes without losing any content. I'm not able to export the collections or move posts within them to a different collection type. I'd like to avoid having to recreate individual blog posts. I have the .conf, .item, and .list files to reference if needed.

If you can help me, you're a life-saver! Thanks.