I want to delete a role

[lenleo]

How do I delete my character data and start playing again? The league level is too high and wants to start over.

[Maewen Von Sternberg]

Not sure you can but if you really want to try : uninstall the game and remove it from your steam account, wait a week and croos fingers when reinstalling it ^^
Or create a new steam account ^^

[Capt.Luke]

just lose match over and over again

[FarAwayBuyer]

That doesn't work. Have you tried deleting the game (including all local files) from your Steam Account? Otherwise, you can find the game directly via the company's website with a quick Google search and just create another User ID. That'd require playing outside Steam, which is certainly a hassle.