Adding Rattletrap as a sound deadening material to inside of our passenger van. I have removed both rear panels and the tail gate panel with no problems. The sliding door is free from the bottom up but is still connected along its top edge right below the window. Can't seem to get it to release at all. One advisor states I have to disconnect the latch assembly before I can remove the panel. I have the cable disconnected but can't seem to disconnect the lock knob. To me it appears that the latch assembly shouldn't have to be removed and there must be a 'key' or 'release' mechanism some where. Any experience or advice on taking off the interior panel of sliding door?