The first and usually only step is to download all your transaction data from Salt Lending and import them into Koinly. There are a couple of ways you can do that:
If you want to use CSV files, you must make sure to import your deposits/withdrawals and trades for ALL previous years - not just the current one!
That's all you have to do. Don't forget to tag your airdrops/forks so they appear as Income on your generated cryptocurrency tax documents!