I believe it's prety much the same as using python on a regular ArduPilot...
Read this:
Welcome to DroneKit-Python’s documentation!
DroneKit Python enables hackers to run code onboard the 3D Robotics Solo drone to drive interesting behaviors and applications. Learn DK Python here.
www.ddmckinnon.com
3drobotics.github.io
Solo-specific enhancements to DroneKit-Python. Contribute to dronekit/dronekit-python-solo development by creating an account on GitHub.
github.com
I never did this on a SOLO, but I do use it on my "production" quad with ArduCopter and RPiZero with an ALFA wifi card and Rpi camera for a HD stream.
Using RPi as companion computer to do the hard stuff, and ArduCopter to do the flying.
It's actually pretty easy once you figure it out, plus on a SOLO you dont have to deal with the installations and routing configuration. Go for it.