Hi there, I didn't upgrade to LED's on the interior as I heard they will flicker as it fades out. the removal of the bulbs from the holder is a real pain. If you look there will be two metal tabs with the wires from the bulb bent over them, you can push the tab up and then SNAP the little wires from the bulb and then it will be completely free. Here is a video which should help!
https://www.youtube.com/watch?v=k6TmLbOIeuE
If you do change to LED and they don't flicker and fade properly please could you leave a link to the product you bought as I would like to upgrade to LED in mine. At the moment I have the cheap blue painted "xenon" bulbs in there which do produce a white light but I would like something brighter!