Every part and tool for this instructable I've found at home. That's why it cost 0$.
Step 1: Materials & Tools
Step 2: Cutting the Parts
Step 3: Repair the Broken Fastening
Make two holes in the cap and tighten to broken fastening.
Then attach with glue or something else to make it reliable. Maybe Sugru is the best way.
You may use a Crop-a-dile or anything else to connect the parts .
Connecting the parts avoid curvature relative to each other.