images – How to bulk change media item’s link?

Ok, so I have this website, If you scroll down, you’ll notice that there are areas where the images don’t show up. They point to some other website which I took down. For example, in that link above, the first image that doesn’t show up is this:


What I want to do is change the “studylions” part to “community.entermedschool”. But I want to do it in bulk for all the images in the website which start with “studylions”. How can I do this?

Any help is much appreciated!