When removing the vents from the top part you just have to take time and be patient. There are 4 clips along the top edge and some on the sides so just lever these up and wiggle the vent pets whilst you it to separate.
As for the hazard and airbag light - so long as you don't turn the ignition on with them unplugged you will be fine
Slightly shameless side note - but i have a spare top section which I am selling on eBay at the moment if you want one to wrap without taking the other one out? Could do it for £12 delivered frost class for a fellow member on here rather than the eBay.
[ebay]160934066594[/ebay] if interested :)
Not totally sure on the RCD but I don't imagine it would come apart