Try placing the speaker flat on the floor . There should be four bolts just back from the spike / gold leg holes. Undo the bolts and the black plinth should come off. I believe the front panel does not come off from the outside, rather is secured from the inside.
You might also try to unscrew the crossover plate (on mine it is attached with wood screws into the cabinet) and as bignerd states hot wire another tweeter into the array and see if it works (the wires are very short and are soldered, so it may be difficult). The tweeter and the midrange in the uni-Q are seperate items, the tweeter sits in the middle of the midcone. I have helped a friend replace the tweeter in a set of the Q series, so am assuming the reference to be the same.
From what my dealer said when they took mine apart, under warrenty, it is not an easy task, and is very time consuming and they needed a special tool.
If the above does not work I agree with Bignerd...call Kef and ask
