<aside> 🔧 This is the build guide for the Sofle Choc Kit from https://choc.brianlow.com/
</aside>
I recommend coming back to this step after you know the rest of the keyboard is working (or at least a few switches are working). A short on a LED can cause a variety of problems and it is hard to isolate. Once you have the keyboard working you can install a few LEDs and test as you go.
LEDs are placed on the bottom of the PCB.
The lens should point up through the PCB so they shine into the bottom of the switch. One leg will have a diagonal cut. This cut leg should be aligned with the triangular marking on the PCB.
To solder: tin one pad, place the LED and hold using tweezers, apply heat to the leg until the solder melts and the LED is flush with the board. Now the remaining legs can be soldered without the component moving.
The LEDs are sensitive to heat. Let the LED cool between soldering each leg. Use the lowest heat needed for your solder.
The LEDs are wired in one long chain. If a LED is not working, replace the LED and the LED proceeding it. Sometimes just the output of a LED is damaged. The full chain does not need to be installed if you want to test a partially built board.