Hard reset TP-LINK TL-WA5110G

Factory reset (Hard reset) Make sure the router is powered ON. The reset button is on the rear panel. Press and hold it for 5 seconds. The AP will reboot after the System LED on the front panel flashes 5 times. You might need a paper clip or another thin object to push in the reset button-hole.
Firmware Firmware link
Default username admin
Default password admin
Default IP address 192.168.1.254