Summarize this article:

Many router pages have a Settings or a Wireless Settings section at the top or bottom of the page.  If you can't find a "Settings" option, look for a gear-shaped icon or a triangle-shaped icon in one of the corners of the page. Clicking such an icon will usually prompt a drop-down menu with options such as Settings. You may first have to click a Wireless tab or section. Doing so will take you to your router's Settings page, which is where you'll make all of the changes needed to secure your wireless home network. You'll usually find them on the main Settings page, but if your router's Settings page has different categories listed by tabs, you may have to click on the Security or Password tab first. If you see a text field with your network's name in it, change your network name to something inconspicuous (e.g., "Linksys-2018"). You don't have to change the network name if you're using the default network name with which the router was programmed. Find the current password that you're using, then change it to something difficult to guess. Most routers allow for up to 16 characters for a password, so use all 16 if possible.  Your password should include both upper- and lower-case letters, numbers, and symbols. Avoid using any personal information (e.g., a pet's name) for the password. You may first have to enter the current password. There should be a Save (or similar) button at the bottom of the page, so click it to save your new router password.  You may have to scroll down to see this option. If your router signs your computer out of your network at this point, connect to your network with the new password before proceeding.

Summary:
Find the "Settings" section. Click the Settings option. Look for your network's name and password. Change the network name (SSID) if possible. Change the password. Save your changes.