Turn off power at the breaker
Verify the circuit is de-energized with a voltage tester
Remove the switch cover plates and pull out both 3-way switches
Identify the common terminal on each switch
Connect the always-hot wire to the common terminal of the first switch
Connect the wire going to the light fixture to the common terminal of the second switch
Connect the two traveler wires between the traveler terminals on both switches
Connect the neutral wires together in the box if present
Connect the ground wires to the green ground screw and bond to the metal box if required
Reinstall the switches into the boxes
Attach the cover plates
Restore power at the breaker
Test the light from both switches