The first step is to download all your data from Radar Relay and upload it into Koinly. There are a few ways you can do this:
Note that 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 it. The only other thing to keep in mind is to tag your airdrops/forks so they appear as Income on your final crypto tax documents!