Step 1: Get the Supplies
Step 2: Measure and cut the PVC
Cut the pipe so that there is not too much overlap such that the axel bolt gets in the way. Also, you'll need to measure the proper length of height, considering that you will be connecting a "T" to one end.
As you will see, the "T" allows an extended support to run towards the rear of the bike. The diameter of the "T" (and "L") just happens to be the right size to fit in the hole groove of the basket, but not through it. This is key. You'll see this in the next step.