Our mailboxes looked like this. I took matters into my own hands. Goo gone and a razor blade got the sticky mishmash of labels off. I sanded them with a fine grade sandpaper and gave them several coats of black Chalkboard Paint .
Next, I used a chalk pen to write all the names directly on the box. It's a great solution for an apartment, because we can just wipe it clean when someone moves in or out and add the new line up of names. Our mail carrier actually thanked me. "I can see who lives here!" she said.