You might be having a small problem to take off the teeth of your Crown zipper when you need to shorten it. Because Crown Zipper teeth are molded right on the tape, not clamped on like any other manufacturer's zippers such as Talon, Conmar. . . . This molded teeth method definitely made Crown Zipper tougher than the other manufacturer's zippers. But on the other hand, it will be also tougher for you to take off the teeth at your Crown Zipper. Refer to the following instruction for your shortening Crown zippers.
[ How to take off the teeth. ]
Before you start to shorten your Crown zipper, practice some times using extra part of your zipper.
1) First, cut the two points of (A) by a nipper or any tool without damaging zip tape. (Refer to the above left illustration.) It usually needs to take off teeth 1" long.
At facing to the zipper oppositely, the right top tooth should be higher than the left top tooth when you complete the shortening. (Refer to the above right image.)
2) Turn off the divided 3 parts of (B) gently from the tape by a needle nose pliers or any tool without damaging the zip tape.
[ How to put the unique top stops on your Crown zipper. ]
This unique top stops can be seen only at Crown 2nd model #7. And it actually needs a special press tool for pressing the pin of the unique top stops. But it should be possible for you to reconstruct a nipper or any suitable tool as a substitute for the special press tool somehow.
1) At facing to the zipper oppositely, the top stop should be put at the left top of the zipper. First, put the notched metal disk (A) into the space between the top tooth and 2nd tooth facing the notched side to the zip tape. (Refer to the left images.)
2) Then, put the pin (B) into the hall of the teeth through the disk hall from the top of the tooth. (Refer to the left bottom image.)
3) Press the pin at the space between the 2nd tooth and 3rd tooth from the top by your reconstructed press tool.