Installing a DRO on the Knee of a Tree 2UVR Milling Machine

I use the knee on my mill A LOT, and I've wished it had a DRO ever since I bought it. Well...now it does. It is a cheap and simple unit with only 0.001" resolution, but I think it is going to be completely adequate for my needs. Come along while I solve some problems and get this working. The DRO is from Amazon: https://www.amazon.com/gp/product/B0160GAV4W