Does anyone know how the sunvisor clip / holder comes off? There is a very small hole in the back of the thing and probably a spring clip or something. Any ideas?

you have to twist it almost 90 degrees and then gently pry it out. there is like a cross pattern on it and it goes into a simmilar cross pattern and then it twist and locks into place. Sometimes they are tight though thats why you may have to persuade it a bit.