The first and usually only step is to download all your transaction data from Omgfin and import them into Koinly. There are a couple of ways you can do this:
If you decide to import CSV files, you have to make sure to import your deposits/withdrawals and trades for ALL years and not just the current one!
That's pretty much it. Don't forget to tag your airdrops/forks so they show up as Income on your final crypto tax forms!