You can change your name for once through the Settings menu in Toy Blast. 
  • Tap on the Settings Menu button (it looks like a gear!)
  • Tap the Change Name button
  • Enter your name that you would like to use
  • Enter the same name a second time to confirm the spelling
  • Tap the Yes button to change your name 
You cannot change your name for a second time, so please be sure that you enter your name correctly.