What light? There are 2. One looks like this: (!) and one like this: TPMS
(!) means one or more tires is low on pressure
TPMS means the system has a problem
If you have (!) and you are 100% sure that all 4 tires are at the correct pressure then one of the sensors was damaged when the tires were replaced.
There is no need to "reset" the TPMS system because it resets itself when it receives full pressure signals from all 4 sensors. I know this for a fact because my winter tires are on a second set of wheels without TPMS sensors. I drive all winter with the TPMS light on. In the spring when I put the summer tires and wheels that contain the sensors back on the car the light goes out within a mile of driving the car.