The first - and in most cases, the only - step is to download all your transaction data from BitAsset and import them to Koinly. There are a few ways you can do that:
Note that if you want to use 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. The only other thing to keep in mind is to tag your airdrops/forks so they show up as Income on your final cryptocurrency tax documents!