Hard reset TP-LINK TL-R402M

Factory reset (Hard reset) The reset button is located on the front panel of the router and it is clearly marked with a RESET label. Power ON the router and use a thin object (like a paper clip) to press in the reset button/hole and hold for about 5 seconds. Release and wait for the rooter to reboot and restore its factory default settings.
Firmware Firmware link
Default username admin
Default password admin
Default IP address 192.168.0.1 or 192.168.1.1