Router>en
Router# erase startup-config
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
[OK]
Erase of nvram: complete
Router# reload
System configuration has been modified. Save? [yes/no]: Y
Proceed with reload? [confirm]
After reloading
Would you like to enter the initial configuration dialog? [Yes/No]:
I would choose No and configure myself from here 🙂