You should be able to change the network name, PW, etc., at the router's online administrative site.
First, make sure the system has Internet access, open Control Panel/Network and Sharing Center, click on Local Area Connection/Details, and write down the router's "IPv4 Default Gateway" address.
Next, open your Internet browser, enter the IPv4 address in the address box at the top of the screen, press Enter, type your User ID and PW, and click OK.
You should now be able to make any desired changes.