Here is the video on instructions to cut down a paddle, as well as some written steps.
1) Purchase some two-part epoxy. You can find it in your local drug or hardware store; the kind that comes in a syringe works well.
2) Cut the paddle two inches shorter than the desired finished length (because the handle is two inches).
3) Smooth the cut edge with sandpaper (be careful because carbon splinters are painful).
4) Mix a small amount of two-part epoxy and wet both the inside of the shaft and the part of the outside of the handle to be inserted into the shaft.
5) Insert the handle.
6) Wipe off any excess and allow to dry.
I use this paddle a lot in Rivers and the Dynal blade really takes a beating. The wide catch of the paddle blade gives excellent power per stroke. The fiberglass shaft adds to the power with a good natural flex and a solid response. Because this paddle is so durable I end up using it most of the time.
Bought this for my wife and she found the paddle too heavy. The blade had a "dull" feel in the water and the shaft was too flexible. Since she only paddles wide flatwater, this was not for her. It looks perfect for folks doing rivers and "rock gardens" (seems very tough).