Please watch my video for assembly https://youtu.be/RdnuUNqGxY4
The spring release I used is actually from a cheap Pokeball I had around at home that you can buy online for a few bucks. Some 1.75mm filament will also work as a hinge that can be opened manually. You may need to drill or melt a slightly bigger if you want to do that.
The holes where the wire go in for the button may not print properly because of how fine they are, so you may need to drill or heat up a pin to puncture the holes instead.
I printed mine with auto supports. If you do the same, make sure to remove any little pieces where the button clicks into position on the upper and lower inside parts as they can get easily missed. If not the button might be too sensitive.