Use the Roku mobile app on your phone
Connect your phone to the same WiFi network your Roku was previously using
Open the Roku app
Tap Devices
Select your Roku device
Use the app’s remote feature to navigate Roku settings
Go to Settings
Select Network
Choose Set up connection
Select Wireless
Pick your WiFi network
Enter the WiFi password
If your Roku is not on the same network, use a mobile hotspot with the same network name and password as the old WiFi
Connect Roku to that hotspot
Open the Roku app and control the device
Change the Roku WiFi settings to your new network
If needed, use an Ethernet cable on a Roku model with an Ethernet port
If needed, use a universal IR remote or replacement Roku remote
If needed, reset the Roku and set it up again using the Roku app