If you've got a Voice Remote, then open the battery compartment and press the Pairing button for five seconds until the light starts flashing. If you don't see the button, just press the Back and Home buttons at the same time, and then hold them down. Simple Remotes (IR) don't need pairingjust aim it at the TV and check that the batteries are still good. If it rejects the connection again, disconnect your Roku device for a minute and then plug it back to refresh the connection.