I have a hell CMS to work with and am wondering if i can the following with jQuery (or just straight up JS)

images are being displayed with no ID's or classes. am wondering if i can replace images based on the src value

pseudo code would be uh.....something like

find img where src = /img/00789-reg-1.jpg';
and replace src value with ='img/much-better-img.jpg';

thanks -