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.