The first and usually only step is to download all your transaction data from NLexch and import them into Koinly. There are a few ways you can do this:
Note that if you decide to use CSV files, you need to make sure to import your deposits/withdrawals and trades for ALL previous years and not just the current one!
That's all you have to do. The only other thing to keep in mind is to tag your airdrops/forks so they show up as Income on your generated cryptocurrency tax documents!