I have heard people say theyve removed the wiring without (ive never even got that far) i always have a good tug ( ) and see if it comes out, and never have. But one thing for certain, they are hard enough to get out, let alone get back up.

Above is the only way IMO, my first car didn't have a sun roof being a poverty model and i ran wires up the A pillar with ease to fit a roof clock