If you want to use it as a modem/router again simply push a paperclip or similar into the factory reset hole and keep the swtch closed for 20 seconds. Then leave it and it will reset to the same condition as when supplied. Note it will take several minutes to bring you back on line.
Alternatively just enter 192.168.1.254/expert_user.html into the address field , not the search field of a browser. If it doesn't work try a different browser.
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