The first and usually the only step is to download all your data from bitgo wallet and upload it into Koinly. There are a few ways you can do this:
Note that if you decide to use CSV files, you have 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. Don't forget to tag your airdrops/forks so they show up as Income on your final cryptocurrency tax documents!