The first and usually only step is to download all your data from Abra and upload it to Koinly. There are a few ways you can do this:
Note that if you want to use CSV files, you need to make sure to import your deposits/withdrawals and trades for ALL years !
That's pretty much it. The only other thing to be vary of is to tag your airdrops/forks so they appear as Income on your generated cryptocurrency tax forms!