C6220 How do I change password to modem

[Sunnykmischke]

I need help changing my password for internet connection. 

Netgear : Router modem Model # C6220

I dont know what Firmware is and OS is help please 

[FURRYe38]

Factory reset the modem and walk thru the setup wizard with a wired PC and web browser. 

Review the installation guide or user manual for additional help and information regarding setup.