The I2C lines on the LiDAR harness shouldn't be trimmed much; they similarly need to be 10 cm (4 in). These are too short in the photo and unfortunately the LiDAR only comes with one harness [the author ended up trimming them all the way back and adding silicon wires to get the required length].
Attach the power and I2C lines (blue is SDA, green is SCL) to the Feather. This can be done by soldering to the corresponding pins on the back or the Feather (power to the USB pin).
Route the battery, Feather power, and LiDAR I2C lines into their respective notches and carefully put the cover in place, securing it with 4 M3 bolts. Using heated M3 inserts in the body holes is recommended as shown in the above photos.
Turn the switch on and you should soon see a distance reading. It can take a short while for the unit to calibrate and the reading to settle.