I'm not familiar with the Enertia+ either, so you might need to do some digging to find where to connect. It might be similar to how the Empulse is, with a 3-pin CAN connector called "controller can" or something similar.
I have a biz set up for consulting if you need a lot of help, as it takes a bit of time for me to dig and research how to connect. Once connected, encoder commissioning isn't that hard and I have a document for it from Brammo.
You'd need an IXXAT USB to CAN cable (which I sell as well) and DVT software (included when you purchase an IXXAT from me). I also rent it for $50 for 2 weeks, with $450 deposit ($500 total).