You can update your name or signature very quickly if you have created a full account on remind.com or in the Remind app.
- iOS App: On the Classes list, tap the person icon in the upper right.
- Android app: Click on the three vertical dots in the top right (or the menu button on your device), then "Account"
You can also log into your account online and click your name in the upper left. Click "Account" and edit the name on that screen.