You may have to adjust the xy-size compensation on the inner parts to make it fit perfectly, or slightly post-process the holes depending on the calibration of your printer. For me, everything fit perfectly except the hole for the power-plug which needed to be sanded down a little to fit.

The power attachment is hot-glued in place and the LED-strip is attached with the tape on the back. The light sensor is also attached with hot glue, as shown in picture 10.

I put the lower and middle inner part in the bottom enclosure, marked the middle of the gap with a sharp object, then marked a line with a sharpie in order to correctly align the LED. (See picture four through seven)

All credit goes to @Mawoka for making a great open source option and base for me to build upon. The soldering and parts are all exactly the same as indicated in their original work. See: https://www.printables.com/model/919380-td-free-an-open-source-alternative-to-the-td-1, https://github.com/mawoka-myblock/td-free