how to kill of a motion sensor light. will puting tape on the sensor work?

Answer 1

There has to be a switch somewhere, so you can just turn it off. The tape trick will work and you can still use he light as all motion detector lights come on for one 'on time' when power is first applied - so that you can togle the switch to force the light on if you need it.

It's usually not hard to take them apart and connect the wires from the light switch directly to the light, bypassing the sensor. I've never seen one that didn't have wire nuts inside that would let you take the sensor out of the loop.

Answer 2

It probably will, test it and see. The test will be cheap, easy and fast.
If it doesn't work, disassemble the fixture and install a single pole double throw toggle switch to bypass the sensor, shutting off the sensor and sending the power to the light so you can control the light from a standard switch located inside your home (I'm assuming there is such a switch already installed.)
That toggle switch will let you switch the fixture from automatic back to manual at your convenience.
The tape would render the entire fixture useless. If it can't detect motion, the light won't come on at all.