How do I charge the 4k remote

Hi Helpplesse999,

To charge your Siri Remote, which looks like one of these:

you'll need a Lightning/USB-C cable (depending on which port the Siri Remote uses). Plug the Lightning/USB-C end into the bottom of the Siri Remote, and the other end into either a computer port or a power adapter.

See here: Charge the Siri Remote

If you have an Apple Remote like this:

the battery is non rechargeable and needs to be replaced.

Use a coin to open the battery door on the back, then replace it with a CR2032 or BR2032 battery.

Apple Remote (old): How to replace the battery in your Apple Remote

Hope that helps!