This is not an in-depth tutorial, but a pile of resources for future reference.
If your keyboard is mechanical and it uses QMK Firmware, try holding LeftShift+RightShift+N to enable nkro.
If that doesn't work, check the QMK docs.
If you're really savvy, you can manually edit the firmware code. The most important piece of code is the #define FORCE_NKRO in the config.h file. More information on qmk and steno can be found here.
You can also check out the_uni branch on my fork of the qmk firmware github to see an example of the firmware that a Uni uses.