As per EOS website: "Within 23 hours after the end of the final period on June 1, 2018 at 22:59:59 UTC, all EOS Tokens will become fixed (ie. frozen) and will become non-transferrable on the Ethereum blockchain."
Here's a very simple step by step instructions on how to register your current ERC20 EOS tokens to be ready for the EOS blockchain launch.
1. Go to eos.io
2. Scroll down to GET EOS
3. Scroll down to Participation Instructions
4. Click on Register tab
5. Scroll down to where you see this:
My favorite is MyEtherWallet and the safest way is access your wallet using either Trezor or Ledger
6. Click on GENERATE EOS KEYS and make sure you save them securely. If you lose your keys, you wouldn't be able to access your EOS.
7. Follow the remaining simple steps outlined in the image above (which is a screenshot from EOS website). You can refer to the screenshots below that match the steps above:
Now, unlock your Ethereum wallet using the safest way (Trezor or Ledger).
Once you do all the above, you will get the green success bar below with the TX Hash. It's usually very fast, and you can check your transaction status on etherscan.io by pasting the TX Hash, or your public Ethereum address which you have used for registration.
Finally, once your transaction is confirmed, you can double check using the steps below:
Make sure the EOS address you get matches the one you got when you generated the EOS public and private keys at the beginning.