1. Download Cura Lulzbot edition for free here: https://www.lulzbot.com/cura
2. When you get to the Add a Printer step when launching Cura for the first time, add either a Mini or a TAZ 6.
3. Upload your file and adjust as necessary (make yourself a note of adjustments to include in the specific instructions section of the dropoff submission form).
Cura 3.6 (newest version)
Cura 2.6 (what the library uses)
How to install Cura: here
Cura Lulzbot Edition Quick Start Guide: here