The first - and in most cases the only - step is to download all your data from coinzest and upload it to Koinly. There are a couple of ways you can do that:
Note that if you decide to import CSV files, you have to make sure to import your deposits/withdrawals and trades for ALL years - not just the current one!
That's it. Don't forget to tag your airdrops/forks so they appear as Income on your generated crypto tax forms!