A headlock cable installation system includes a headlock assembly, an extension rod, and a flexible headlock cable. The headlock cable installation system is used for installing a pre-connectorized cable assembly. The headlock assembly defines a cavity configured to receive a connectorized end of the pre-connectorized cable assembly. The flexible headlock cable has opposite first and second ends. The first end of the headlock cable is coupled to the headlock assembly, whereas the opposite second end of the headlock cable is adjustably coupled to the extension rod. Adjustment of the second end varies a position of the headlock assembly relative to the extension rod.