Connect your device to the TP-Link router WiFi or use an Ethernet cable
Open a web browser
Enter the router IP address in the address bar
Log in with the router admin username and password
Go to Wireless settings or WiFi settings
Open the Wireless Security or Password section
Enter the new WiFi password
Save or apply the changes
Reconnect your devices using the new password
If needed, log in to the TP-Link admin page and change the admin password under System Tools or Administration
Save the admin password changes