Next step is actual disassembly of each sill.
Using a utility knife (carefully, always cut away from yourself, etc.) get under the corner of the metal plate and begin slicing the quarter inch strip of adhesive backing around the edge of the plate.
Continue cutting around each end and the outside edge to sever the adhesive strip.
Next, use a longer knife such as a steak or pearing knife or long bladed pocket knife to sever the adhesive strip along the back edge. You will have to pry away the metal plate and EL Tape piece to get at it.
Now you should be able to remove the plate from the plastic/rubber sill base. Now begin to peel the original EL tape from it's adhesive strips. These do not require a knife. Peel carefully as you will want to try to reuse some of the adhesive that's there. If you can't save any of it, it's okay, you can use doublestick tape in it's place later if necessary.
Underneath the original EL tape strip are two clear plastic lenses held in place by clear adhesive strips. The same strips held the original EL tape in place. (pardon the blurry picture).