Turn off the Apple Watch if desired and place it face down on a soft, clean surface
Hold the watch so the band slots are facing you
Press the band release button on the back of the watch
Slide the existing band out of the slot
Align the new band connector with the slot
Slide the band in until you feel or hear a click
Gently pull the band to confirm it is locked in place
Repeat for the other side of the band
Make sure the band is oriented correctly for left or right wrist use
Put the watch on and adjust the fit if needed