On the Account popup, the Switch Accounts button allows you to toggle between up to two registered War Paradise accounts. You must first bind your current game to either your Google or Facebook account. If you're unsure how to find the Account popup, from your base view, tap your Commander's picture in the top left corner.
Once on the Profile page, tap the Settings button on the bottom navigation bar to open the Account popup. Tap Bind to begin registering your account.
Once bound, you can then tap Switch Accounts and select the unbound type of account. This will relaunch the game and allow you to start fresh. You will need to complete the tutorial again before you can return to Profile > Accounts > Switch Accounts and toggle back to your original account.
For Example: Start the game, complete the tutorial, navigate to Profile > Accounts > Bind and select Google to bind with your Google Account. Then tap Switch Account and select Facebook; this will relaunch the game. Complete the tutorial again on your second account. Then return to Profile > Accounts and use Switch Account to bounce back and forth between Account 1 and Account 2.