Turn off power at the breaker
Verify power is off with a voltage tester
Identify the line, load, and traveler wires
Connect the line wire to the common terminal on the first switch
Connect the load wire to the common terminal on the second switch
Connect the two traveler wires between the traveler terminals on both switches
Connect the ground wires to the green grounding screws
Connect the neutral wires together if present in the box
Secure all wire connections with wire connectors
Mount the switches in the electrical boxes
Install the switch plates
Restore power at the breaker
Test both switches to confirm proper operation