To edit one of your accounts in your TronWallet app, first tap on the icon on the bottom right of your navigation bar and then select Address Book. There, you will find two tabs: Contacts and Accounts. Tap on the Accounts tab and you will see a list of all your multiple accounts in TronWallet. Tap on any of those accounts to bring up a modal with two options: Edit and Send. Send will take you to the Send screen with the address for that account already filled in. Edit will take you to a form where you can change the name of your account. Once you have decided on a name tap on Edit and your account will be updated and displayed in the accounts list.
Help & Tutorials: https://medium.com/tronwallet-support