An apparatus for installing at least one electrical contact into a socket of a connector housing , the apparatus comprising: a base configured to fixedly support the connector housing ; an alignment guide extending from the base and having a central axis , wherein, with the connector housing fixedly supported by the base , the alignment guide is configured to be parallel to an insertion axis of the socket of the connector housing ; a carrier translatably and pivotally coupled with the alignment guide , wherein, with the connector housing fixedly supported by the base , the carrier is movable parallel to the insertion axis of the socket of the connector housing ; and a tool holder coupled to the carrier , wherein the tool holder has a working axis and only three degrees of freedom relative to the base ; wherein the tool holder comprises a coupler configured to removably retain an insertion tool in the tool holder ; wherein the central axis of the alignment guide is configured to be parallel to the insertion axis of the socket , and the tool holder is coupled to the carrier such that the working axis of the tool holder is parallel to the central axis of the alignment guide ; wherein a minimum distance (MD3) between the central axis of the alignment guide and the working axis of the tool holder is adjustable; wherein the tool holder comprises a tool-holder arm and the carrier comprises a carrier arm pivotally coupled with the tool-holder arm ; and wherein the minimum distance (MD3) between the central axis of the alignment guide and the working axis of the tool holder is adjustable by pivoting the tool-holder arm relative to the carrier arm . a base configured to fixedly support the connector housing ; an alignment guide extending from the base and having a central axis , wherein, with the connector housing fixedly supported by the base , the alignment guide is configured to be parallel to an insertion axis of the socket of the connector housing ; a carrier translatably and pivotally coupled with the alignment guide , wherein, with the connector housing fixedly supported by the base , the carrier is movable parallel to the insertion axis of the socket of the connector housing ; and a tool holder coupled to the carrier , wherein the tool holder has a working axis and only three degrees of freedom relative to the base ; wherein the tool holder comprises a coupler configured to removably retain an insertion tool in the tool holder ; wherein the central axis of the alignment guide is configured to be parallel to the insertion axis of the socket , and the tool holder is coupled to the carrier such that the working axis of the tool holder is parallel to the central axis of the alignment guide ; wherein a minimum distance (MD3) between the central axis of the alignment guide and the working axis of the tool holder is adjustable; wherein the tool holder comprises a tool-holder arm and the carrier comprises a carrier arm pivotally coupled with the tool-holder arm ; and wherein the minimum distance (MD3) between the central axis of the alignment guide and the working axis of the tool holder is adjustable by pivoting the tool-holder arm relative to the carrier arm . <EOS>