1. Unscrew the four screws which are placed on both sides of the saddle, underneath the skirt.
2. Pull off the two panel pieces.
3. Undo the leather over to be able to reach the exchangeable steel gullet plates.
4. Change the steel gullet plates for another one with the required size.
5. Fit the end of the tree points inside the inner pocket.
6. Screw once again the four fixable screws.