Wow, that actually looks really nice! They are simple images, so to change them you can't change the link or code. You will have to change the actual image.
I think you will be able to make your own, looks like you know how to edit and screenshot quite well. =) Google dividers and then find the ones who are free to use (meaning no copyright issues).
I am still more than happy to do another post with loads of dividers if you want. =)
Check out my latest post, might have some interesting edit tools for you if you would like to use them. =)