Slip one piece on the end of the fly line and push it up the line out of the way. Cut the frayed ends of the butt of the connector loop. Open the connector end with a needle, being careful not to fray it more. Push the fly line in just a little and work the braid onto the line a bit more. Repeat many times in small increments.
Heat shrink the tubing by holding it near an incadescent light bulb.
Be careful not to touch the bulb as the tubing will melt. When putting your fly rod sections together start them at a 90 degree angle and slowly twist the section on and in until the guides line up. This will preclude most breaks at or near the ferrules, give better support and making disassembly much easier. We are often asked by beginning fly fishermen what trout flies should they buy to get started. It would not hurt to carry some in 18 and 20.