Attach four M2 standoffs to the Pico W's four mounting holes with M2 nuts.

Attach the Pico W to the case lid with four M2 screws.

Attach the OLED screen with four M2.5 screws and nuts.

Plug the PiCowbell into the Pico W. The STEMMA port on the PiCowbell should be below the USB port on the Pico W.

Connect the OLED to the STEMMA port on the PiCowbell with a STEMMA QT cable.

Route the DS18B20 through the larger opening in the case. Slide the sensor through the clip on the top of the case.

Wrap the excess cable for the DS18B20 into the bottom of the case. Route the LED through the larger side opening.

Close the case with the lid. Mount the LED into the mounting hole on the lid in the cow's bell.