The first step is to download all your data from Infinito Wallet and upload them to Koinly. There are a few ways you can do 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 all you have to do. The only other thing to be vary of is to tag your airdrops/forks so they appear as Income on your generated cryptocurrency tax documents!