the covers pull right out. they're attached to the pillar with metal clips that slide out. You might have to remove the rubber seal around the door first before you can pull cover out. then start pulling the cover our from the top and work you way down. If you need to pull the cover out all the way you have to pull the trim up towards the ceiling after completely the clips from the a pillar.
hope this helps
I had to tackle a job just like this one on my X. I modified the pillars to accomodate the tweeters for my component set. This yielded the best soundstage and imaging in my particular install. If you need any further assistance in removing panels let me know, I removed most of the panels in my X to get all the wiring routed through.
After driving with the new setup this afternoon I discovered that the routing of the microphone cable through their is not a good idea. Too much RFI from the power cords under the cover. I will take out the panel and run the mic the original way under the trim.