I’ve been working on my home grown wired and wireless network a bit this week and found myself needing to reset the Asus RT-AC52U I use as a WiFi access point. The USB WiFi adapter I have attached to my NAS/Router is pretty short ranged, so I ran a network cable across the house so this AP can cover the rest.
Anyway, as is often the case I forgot my credentials. This router actually lets you change the admin login and I am sure I did but have no idea to what.
So, to reset it, find the reset annoyingly located on the bottom of the device and press it with a paperclip until the LEDs start turning off.
Once it is reset, it has reverted to setup mode. In this state it runs an unencrypted WiFi network which you need to connect to and configure the router. It has also defaulted to 192.168.1.1. You will likely get alerted by your browser that you need to log in to a captive portal but the router does not actually prompt for credentials during setup.