changing wifi password

What is the make and model of your router? In general terms you need to log into the router using the admin ID and password then go to the wireless (WiFi) settings and choose the encryption method (WPA2 is preferred) and change the secure password/pass phrase/key. Keep in mind once you do this you need to change the same the secure password/pass phrase/key on ALL of your client machines, smart phones, tablets, etc...etc... DOCUMENT any and all changes to the router that you make... Check the router manufacturers support pages for additional help configuring the router...

I forgot to add that its best to make any changes to the router using an Ethernet cable versus WiFi. That way if you screw something up you can recover easily.

Hi  cant find answer,

Here is a link to a site with some generic login information.  Copy and paste this into a new browser window - http://router123.com/.  Login with the corresponding router information based on the brand that you have.  If yours is not on the list or the login information does not work, you may want to consult the router manufacturer.