I have Roku Ultra Lt. How do I cut the Roku off and not the TV??
Your title and question don't seem to be the same issue. I believe the remote can be unpaired in the Settings/Remote menu. But your message seems to be asking how to turn off the Roku but not the TV with the power button on the remote. Actually, that power button does not "turn off" the Roku. It remains running at all times. The power button only controls the TV. If you want to use the TV for something other than then Roku, then you must use the TV remote and change inputs to whatever you want to use. But the Roku remains on regardless of what your TV is doing.
That's also why you always need to stop streaming anything before stopping to use the Roku. It will continue to stream if you leave it playing but turn the TV off or change to another input.
Dan Roku Stick (3600), Ultra (4640), Ultra (4670), Ultra (4800), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.