4. The improvement of claim 1 wherein the insert being rotated into a locked position above the retainer with the second channel aligned with the first channel by the first manipulation tool in the groove on the interior surface of the insert.
4. The improvement of claim 1 wherein the insert being rotated into a locked position above the retainer with the second channel aligned with the first channel by the first manipulation tool in the groove on the interior surface of the insert. 5. The improvement of claim 4 wherein the insert outwardly extending arm portions are received by an inner cylindrical surface of the receiver top portion during rotation of the insert with respect to the receiver.