Wireless network. Name/password change

I renamed my home  network for ease of reference.  I also revised the password so I could connect more easily than use the password that came from. TMB on the Gateway label.  I got  my tablets connected   via  wireless but now I need to connect my smart TV to the Gateway network, and the connection keeps failing when the password is halfway e there (4 words. Interstate by periods.   How can I change the ID name as password to shorten them?