To connect AirPods to another phone, first make sure the AirPods are disconnected from the previous device.
Then, turn on Bluetooth on your new phone.
Locate the pairing button on the AirPods' charging case and hold it down for a few seconds until the indicator starts blinking.
In your new phone's Bluetooth Settings, locate the AirPods and tap Pair.
Once paired, the AirPods will be connected to the new phone and ready to start using. Note that the pairing steps may vary from phone to phone, but the basics are similar.