How do I reset a password that I have forgoten

For that first press RESET button it is in back side of router.
Press it for 10 seconds.
Then connect t\router to computer with ethernet cable.
Then you can access it's configuration with http://192.168.1.1
or
http://192.168.0.1
type user as "admin" and password as "admin" or blank or "password"
Then click on wireless then enable wep security then add new password.
Configure WAN settings as your internet service provider settings.
Enable DHCP.Then save settings and restart router.
Let me know if you need further assistance.
Thanks.