Are you wanting to do a complete oil change or just the outer? Outer is super easy but considering the inner and outer mix it's not the best option. Doing a complete oil change is a lot more involved but well worth it IMO.
I did a video showing how to completely service the Marzocchi fork. A lot of steps you can skip for either type of fluid change. Hope it helps.
https://youtu.be/dbKjhvFl7AQ