The weatherpack connectors would replace the existing connector... both sides... from the switch and from the wiring harness. You'll have to cut, strip and crimp the new "pin connectors" on each wire... 16 in all.
The alternative is you just find a source for the pin connectors in the existing 8 wire connector and reuse the plastic insulator. Cut the bad wires back past the breaks and cut, strip and crimp the new connectors. 8 wires in all.
The weatherpack is a superior connector, easy to install and pretty foolproof to disconnect and reconnect, but if you don't want to change the connector from the switch, then the weatherpack isn't going interchange.