It is not difficult to change your WiFi password, just follow the steps below.
On a computer connected to your network open your web browser and enter your router address there. Standard router addresses are 192.168.1.1, 192.168.0.1, 192.168.2.1, or 10.0.1.1 (Apple) or 10.0.0.1 (Xfinity WiFi). In case you can't connect to WiFi because you misplaced the password, use an Ethernet cable to connect directly to the router. In some cases you can use a designated software for your router settings.
If you have never changed your router's login details, look on the outside of your device for its username and password, or you can try an online search according to your router's model. In case you changed the login details previously, find the Reset button on your router, press it and hold for about 30 seconds. Once settings are reset to default you can again look at the outside of your router to use the manufacturer's default login details.
After you have successfully logged in to your router, open Wireless section of its configuration page. It may have a slightly different name in different brands of devices, but shouldn't be hard to determine. Then proceed to Wireless Security page.
Find the box named "Password", "Passphrase" or "Shared Key". There you can enter your new password and re-enter it to verify.
WEP, WPA, and WPA2 are three main types of wireless encryption. WPA2 provides the most security, however it may not support some of the older devices, so you may connect to WPA or WPA/WPA2. WEP has been superseded by newer protocols quite some time ago, as it doesn't provide the needed security anymore and can be hacked easily. Using WEP encryption is not recommended.
Change the name of your network from a default one to something more unique, but make sure not to include any personally identifiable information, as this name will be visible to everyone looking for networks to connect. Usually a router with default name is considered to be an easier hacking target.
Click Apply or Save button to finalize the process and remember your new settings. Now you can use your new WiFi password to connect to your wireless network.
Your secure and strong WiFi network can be also set up to perfection with the help of NetSpot - it can help you eliminate dead zones and weak signal all around your network space.