If you have admin credentials, you can telnet into your router via cmd
telnet <router_ip>
It will ask you to enter the username and password (uses same user:pass as in the router web interface)
Once you've logged in, do:
tcapi show Account_Entry0
It should output the Silkent admin user info, you need to find this like:
display_mask=FF FF F7 BF 3F DF FF FF FF
Copy the parameter of display_mask and now do:
tcapi set Account_Entry1 display_mask "FF FF F7 BF 3F DF FF FF FF"
This now sets elevated privileges to "user:user" account in your router.
Even if they change the password and/or username again, you'll still be able to login with the regular user account and have full access to your router
