Help me log into my home wireless network?

My son has went on holiday and I cannot log into our home wireless network, please help, our network is hidden but I know the network name and password, but every time I try to log in it says "see administrator". Someone suggested that I enter our router's ip address into the browser and then entering "admin" as the username and not entering a password, or entering "admin" as the username and "admin" as the password, but that did not work since my son changed the password, someone please help I am on dialysis and I cannot travel frequently to the internet cafe.