An installation system for installing a vertebral stabilization system. The system includes an implant guide and an insert. The implant guide includes a handle and a shaft extending from the handle. The distal end of the shaft is configured for engagement with a head portion of a vertebral anchor. The shaft has flexibility characteristics allowing the shaft to flexibly bend between a first configuration and a second configuration. The insert is slidably disposed along the shaft of the implant guide. The insert inhibits the shaft from bending from the second configuration to the first configuration.
