The first and usually the only step is to download all your data from BTC China and import them to Koinly. There are a couple of ways you can do this:
If you want to import CSV files, you have to make sure to import your deposits/withdrawals and trades for ALL previous years !
That's all you have to do. The only other thing to be vary of is to tag your airdrops/forks so they show up as Income on your generated crypto tax reports!