To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).
To use in CPython, `pip3 install adafruit-circuitpython-displayio-ssd1305`.
Read the [docs](http://circuitpython.readthedocs.io/projects/displayio-ssd1305/en/latest/) for info on how to use it.