I'm still working on it, but I've cut out quite a bit. Start with Chrome, and work your way down.
When you get to email, Gmail has a very convenient forwarding feature so you can forward all email to the new one while you change accounts and whatnot. I made a new account elsewhere, and I have a separate folder for email from my old Gmail and my new email. Every so often I'll go fix an account or two, so I'm making steady progress.
For me, docs/drive is the hardest, so I'm doing it last. I'm playing with self-hosted options, and am still in an adjustment period.
Getting away from Google Maps has been a tough one. There aren't many options there, it's either Google, Apple, Microsoft, or OpenStreetMap.
I've been contributing to OSM for my local area as much as possible to update businesses and their opening hours, website, etc., but it's not a small task.
Remember, it's not an all-or-nothing situation, every step you take away from google helps. And you can always reevaluate later, and take time to figure out what works best for you.
