How do you change the frequency on a hunter ceiling fan and its remote to se if it can work

You would have to change the crystal in the transmitter. There are little switches on some remotes that have to match the ones on the fan.

Open the canopy at the ceiling and pull out the receiver enough so you can see the dip switches. Move all switches to either I or O. Now open the handheld remote and move its switches to match what you did on the receiver. Use a test probe and test the black and white wires feeding from the ceiling box to confirm power reaching the receiver. Now press your fan or light button on the remote and test for power coming out of the receiver. The blue and white should be hot if you pressed the light button. The black and white should be hot if you pushed the fan button.