Go to Tronscan and sign in to your account, make sure you have enough TRON power by freezing your TRX on your account page.
After you acquired some TRON power, you may begin voting by clicking on TRON SR > VOTES on the main menu.
Click on the Click here to Start Voting button to begin the voting process.
Select the super representative candidate that you would like to vote for. To add votes to this SR, click the green + button to add votes. You can add as many or as little as you like. Press the red – button to remove votes.
Once you have entered as many votes as you would like for the SR candidate, click the green SUBMIT VOTES button.
You will be notified that your vote was successful (confirmation is required if you sign in with TronLink or Ledger).
