You can find the full instructions on the original model (https://www.thingiverse.com/thing:3596569). My goal with this remix and edit was to adjust the disc insert to fit non-branded ones while still fitting the keycaps well. 

You can buy the disc I used in bulk for $12.99 here (https://www.amazon.com/gp/product/B076SFTF4T)

You can buy a 70-pack of switches with keycaps here for $8.99 (https://www.amazon.com/gp/product/B07CG7VTGD/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1)

This is a great, simple way to make an adaptive switch/button. I'll be using these with an Xbox Adaptive Controller but I'm sure they have other applications as well. The hardest part is the soldering but the goal with this build was to not require any extra items like screws, springs, etc.