The #5 Polypropylene material is similar to working with wood. You can cut it with a saw, drill it with standard HSS bits, file or sand it.
A hack saw might work best if hand sawing such a small piece. PLEASE
don't use a power saw on such a small item unless your work piece is clamped and your hands are well out of the way .
The poly tube for Whip Rippers is about half the length of a normal tube. So make a mark, then cut. Shape the end with a file or sandpaper.