Image Paths Need Changing

I’m working on a blog that was transferred from here mollyandtheprincess.wordpress.com to mollyandtheprincess.com/about a year ago.
At the time the owner wasn’t told that the images in the posts weren’t moved from mollyandtheprincess.wordpress, so all posts older than a year have their image paths pointing to mollyandtheprincess.wordpress.com

I’m planning to copy the images via ftp into there respective folders and then update the paths using sql statments.

I’m very much a beginner so could someone tell me what tables in the database actually need to be updated.

Many thanks

Stuart