Step 4: Welding!
Once the two "T" pieces and "spacer" piece are cut, the spacer must be welded to one of the "T"s. I am very far from having mastered the art of welding, but after a bit of practice my welds were at least functional. One the spacer is welded, all three pieces must be welded together with two beads along both sides. See pictures for clarity.
Once the welds are finished, they should be ground flat with the angle grinder. Be careful when welding or using the angle grinder on metal; things become very hot very quickly. Don't burn yourself like i did! Once everything is welded together, the holes for the "attachment units" must be drilled. These holes must match the 5/16" diameter of the pins and must be perfectly straight. That is why a drill press or mill is necessary for this step.