I've had those panels out a number of times. 1st: You need one of those readily available plastic trim sticks. Now there are four metal spring clips that hold it on that need to be pried in two different directions a little at a time to prevent breakage of the flimsy plastic retainers inside. 2nd: carefully insert the straight end of the stick into the top of the side edge and pry a little on each side and you should get some release/movement back but don't try to fully remove it yet. 3rd: carefully insert the stick in the bottom edge toward each end and pry a little forward and see if you get a little movement (not too much at first) and then go back to number 2. work back and forth and it will soon come out. the problem is total movement in one direction tends to break the plastic retainers the metal spring fasteners push into. The top needs to free (coming straight back just enough to be out of the retainers first then the bottom will come out in a forward and up direction. I replaced mine because the garage making repairs/checks had broken all but one of the plastic retainers over the years and both 2 bottom panels were only loosely held in place. (My car had 100,000 miles on it when I bought it.) Go slow and easy with the trim stick as you pry.